m_option: fix segfault in parse_chmap
command: simplify sub OSD update

We can just update all OSD elements in these cases. This way we can also
reuse it for commands which need to update the OSD for other reasons.
add osd-scale command

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Modified to add docs for --osd-scale option, and adjusted to the
previous commit by wm4.
demux_mkv: export Matroska title element as metadata
command: use "title" tag for media-title property if available

In connection with the previous commit, this will use the Matroska title
for the media-title property.
options: add --version
options: use case-sensitive comparsion for options

This is better for consistency, and also allows using -V as alias
for --version.
options: add -V as alias for --version

This is a common convention.
mplayer: potentially fix main() return value

The main() function is special, and omitting the return statement would
make it always return 0. And also, mpv_main() actually never returns, it
calls exit() through exit_player() instead. But change it anyway,
because it looks misleading.
options: fix exit code when using help options

Basically a cosmetic change. Fixes github issue #88.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	core/mplayer.c