git: Merge .gitignore files into a single file

We already track a lot of files over the whole directory structure
in the main .gitignore file.  But a few additional ones had been
added into some of the subdirectories.

This unifies all these files into a master file for the whole project,
making it easier to know where to look at and edit if changes needs
to be done.

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Steffan Karger <steffan@karger.me>
Message-Id: <20170120210457.3383-1-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg13916.html
Signed-off-by: David Sommerseth <davids@openvpn.net>

.gitignore

@@ -51,11 +51,15 @@ config-msvc-local.h
 config-msvc-version.h
 doc/openvpn.8.html
 distro/rpm/openvpn.spec
+sample/sample-keys/sample-ca/
+vendor/.build
+vendor/dist
 
 tests/t_client.sh
 tests/t_client-*-20??????-??????/
 t_client.rc
 t_client_ips.rc
+tests/unit_tests/**/*_testdriver
 
 src/openvpn/openvpn
 include/openvpn-plugin.h

sample/sample-keys/.gitignore

@@ -1 +0,0 @@
-sample-ca/

tests/unit_tests/.gitignore

@@ -1 +0,0 @@
-*_testdriver

vendor/.gitignore

@@ -1,2 +0,0 @@
-.build/
-dist/