New icons, icon generator script, night mode logic

Added new icons, both holo light and holo dark, taken from https://google.github.io/material-design-icons/
Added script to generate pngs from svgs.  Makes icons for all sizes and themes given. Includes modified svgs to use as source.
Added some night-mode logic[1] to use icons.

Remove ic_menu_manage

Script generates holo-light icons using:
  Color: #333333
  Enabled: 60% opacity
  Disabled: 30% opacity

The following icons (and _dark versions) added to  mdpi, hdpi, xhdpi, xxhdip.

ic_action_accept.png
ic_action_camera.png
ic_action_cancel.png
ic_action_email.png
ic_action_import_export.png
ic_action_mic.png
ic_action_replay.png
ic_action_search.png
ic_action_settings.png
ic_action_storage.png
ic_action_time.png
ic_dialog_alert.png
ic_dialog_info.png
ic_menu_add.png
ic_menu_edit.png
ic_menu_mark.png
ic_menu_marked.png
ic_menu_night.png
ic_menu_night_checked.png
ic_menu_refresh.png
ic_menu_send.png
ic_menu_sort_by_size.png
ic_menu_statistics.png

ic_menu_refresh (from ic_sync_24px.svg)
ic_action_whiteboard_enable_light (from ic_brush_24px.svg)
ic_menu_revert (from ic_undo_24px.svg)

[1] This is painful, as this code should be made simpler, not more complex, by using themes and attributes.
But the only way to avoid this do a complete rewrite.

AnkiDroid/src/main/java/com/ichi2/anki/CardBrowser.java

@@ -692,7 +692,7 @@ public class CardBrowser extends NavigationDrawerActivity implements ActionBar.O
                 entries[CONTEXT_MENU_DELETE] = res.getString(R.string.card_browser_delete_card);
                 entries[CONTEXT_MENU_DETAILS] = res.getString(R.string.card_editor_preview_card);
                 builder.setTitle("contextmenu");
-                builder.setIcon(R.drawable.ic_menu_manage);
+                // No icon
                 builder.setItems(entries, mContextMenuListener);
                 dialog = builder.create();
                 break;

AnkiDroid/src/main/java/com/ichi2/anki/Reviewer.java

@@ -195,14 +195,30 @@ public class Reviewer extends AbstractFlashcardViewer {
         getMenuInflater().inflate(R.menu.reviewer, menu);
         Resources res = getResources();
         if (mCurrentCard != null && mCurrentCard.note().hasTag("marked")) {
-            menu.findItem(R.id.action_mark_card).setTitle(R.string.menu_unmark_card).setIcon(R.drawable.ic_menu_marked);
+            if (mNightMode) {
+                menu.findItem(R.id.action_mark_card).setTitle(R.string.menu_unmark_card).setIcon(R.drawable.ic_menu_marked_dark);
+            } else {
+                menu.findItem(R.id.action_mark_card).setTitle(R.string.menu_unmark_card).setIcon(R.drawable.ic_menu_marked);
+            }
         } else {
-            menu.findItem(R.id.action_mark_card).setTitle(R.string.menu_mark_card).setIcon(R.drawable.ic_menu_mark);
+            if (mNightMode) {
+                menu.findItem(R.id.action_mark_card).setTitle(R.string.menu_mark_card).setIcon(R.drawable.ic_menu_mark_dark);
+            }else {
+                menu.findItem(R.id.action_mark_card).setTitle(R.string.menu_mark_card).setIcon(R.drawable.ic_menu_mark);
+            }
         }
         if (colOpen() && getCol().undoAvailable()) {
-            menu.findItem(R.id.action_undo).setEnabled(true).setIcon(R.drawable.ic_menu_revert);
+            if (mNightMode) {
+                menu.findItem(R.id.action_undo).setEnabled(true).setIcon(R.drawable.ic_menu_revert_dark);
+            } else {
+                menu.findItem(R.id.action_undo).setEnabled(true).setIcon(R.drawable.ic_menu_revert);
+            }
         } else {
-            menu.findItem(R.id.action_undo).setEnabled(false).setIcon(R.drawable.ic_menu_revert_disabled);
+            if (mNightMode) {
+                menu.findItem(R.id.action_undo).setEnabled(false).setIcon(R.drawable.ic_menu_revert_disabled_dark);
+            } else {
+                menu.findItem(R.id.action_undo).setEnabled(false).setIcon(R.drawable.ic_menu_revert_disabled);
+            }
         }
         if (mPrefWhiteboard) {
             // Check if we can forceably squeeze in 3 items into the action bar, if not hide "show whiteboard"
@@ -223,12 +239,20 @@ public class Reviewer extends AbstractFlashcardViewer {
             menu.findItem(R.id.action_hide_whiteboard).setVisible(true);
             menu.findItem(R.id.action_clear_whiteboard).setVisible(true);
             if (mShowWhiteboard) {
+                if (mNightMode) {
+                    menu.findItem(R.id.action_hide_whiteboard).setIcon(R.drawable.ic_action_whiteboard_enable_dark);
+                } else {
+                    menu.findItem(R.id.action_hide_whiteboard).setIcon(R.drawable.ic_action_whiteboard_enable_light);
+                }
                 //menu.findItem(R.id.action_clear_whiteboard).setIcon(R.drawable.ic_whiteboard_clear_enabled);
-                menu.findItem(R.id.action_hide_whiteboard).setIcon(R.drawable.ic_action_whiteboard_enable_light);
                 menu.findItem(R.id.action_hide_whiteboard).setTitle(R.string.hide_whiteboard);
             } else {
-                //menu.findItem(R.id.action_clear_whiteboard).setIcon(R.drawable.ic_whiteboard_clear_disabled);
-                menu.findItem(R.id.action_hide_whiteboard).setIcon(R.drawable.ic_action_whiteboard_enable_light_disabled);
+                if (mNightMode) {
+                    menu.findItem(R.id.action_hide_whiteboard).setIcon(R.drawable.ic_action_whiteboard_enable_dark_disabled);
+                } else {
+                    menu.findItem(R.id.action_hide_whiteboard).setIcon(R.drawable.ic_action_whiteboard_enable_light_disabled);
+                }
+                    //menu.findItem(R.id.action_clear_whiteboard).setIcon(R.drawable.ic_whiteboard_clear_disabled);
                 menu.findItem(R.id.action_hide_whiteboard).setTitle(R.string.show_whiteboard);
             }
         } else {
@@ -241,9 +265,6 @@ public class Reviewer extends AbstractFlashcardViewer {
         return super.onCreateOptionsMenu(menu);
     }
 
-
-
-
     /*
      * Modify the options menu.
      * Pick the right icons for the whiteboard actions.

AnkiDroid/src/main/java/com/ichi2/anki/dialogs/DeckPickerContextMenu.java

@@ -45,7 +45,7 @@ public class DeckPickerContextMenu extends DialogFragment {
         entries[CONTEXT_MENU_DELETE_DECK] = res.getString(R.string.contextmenu_deckpicker_delete_deck);
         entries[CONTEXT_MENU_EXPORT_DECK] = res.getString(R.string.export);
         builder.setTitle("Context Menu");
-        builder.setIcon(R.drawable.ic_menu_manage);
+        // No icon
         builder.setItems(entries, mContextMenuListener);
         builder.setTitle(getArguments().getString("dialogTitle"));
         StyledDialog dialog = builder.create();