There's a single mp_msg() in path.c, but all path lookup functions seem
to depend on it, so we get a rat-tail of stuff we have to change. This
is probably a good thing though, because we can have the path lookup
functions also access options, so we could allow overriding the default
config path, or ignore the MPV_HOME environment variable, and such
things.
Also take the chance to consistently add talloc_ctx parameters to the
path lookup functions.
Also, this change causes a big mess on configfiles.c. It's the same
issue: everything suddenly needs a (different) context argument. Make it
less wild by providing a mp_load_auto_profiles() function, which
isolates most of it to configfiles.c.
So you can pass a command as list of strings (each item is an argument),
instead of having to worry about escaping and such.
These functions also take an argument for the default command flags. In
particular, this allows setting saner defaults for commands sent by
program code.
Expose this to Lua as mp.send_commandv command (suggestions for a better
name welcome). The Lua version doesn't allow setting the default command
flags, but it can still use command prefixes. The default flags are
different from input.conf, and disable OSD and property expansion.
Since m_option.h and options.h are extremely often included, a lot of
files have to be changed.
Moving path.c/h to options/ is a bit questionable, but since this is
mainly about access to config files (which are also handled in
options/), it's probably ok.
