README: update Contact info with Mailing Lists
README: add clarification about --enable
demux_playlist: add mov RTSPtext tag parser

The quicktime html scripting guide suggests to wrap urls not
necesarly associated with quicktime in a .mov file.
(so that when <embed>ing videos quicktime would be forced.)
These mov files may contain several "Text Hacks".
One of these is RTSPtext.

The suggested/allowed format (as regex) is like:
  RTSPtext[ \r]RTSP://url
See also p.51 of:
https://developer.apple.com/library/mac/documentation/QuickTime/Conceptual/QTScripting_HTML/QTScripting_HTML.pdf
In reality there are also files like (e.g. zdfmediathek.de):
RTSPtext\nrtsp://url\n\n

Lets handle these files as a playlist with one element.
macosx: add webm the filetypes handled by the bundle
stream_dvd: prevent segmentation fault with some broken files

I have a sample where some final chapters are missing. This was causing a
segmentation fault when trying to fetch chapter times for them.

This makes the code ignore those chapters.
mplayer: m_option: fix clang -Wformat compiler warning

Code was using %d format instead %zd to print size_t data.
av_log: show ffmpeg "info" messages with -v only

They are rarely useful in my opinion.

This commit was mainly motivated by this message:

    Video uses a non-standard and wasteful way to store B-frames ('packed B-frames'). Consider using a tool like VirtualDub or avidemux to fix it.

It's what's left over from the "Invalid and inefficient vfw-avi..."
warning that used to be printed when playing avi/divx files. Although
the new message is much better, it's still rather useless and poses
more questions than it answers. Besides, nobody wants to remux a file
when playing it, especially not if playback appears to be completely
fine. (There are some claims that these files raise CPU usage, but even
my old crappy CPU can decode low res avi/divx files at real time at
about x35 playback speed.)
mplayer: don't run heartbeat command while paused

This is commonly used to disable the screensaver with broken/non-
standard X screensavers. During pause, the screensaver should not be
disabled, so not calling this command while paused seems sensible.

See github issue #236.
mp_common: add function which accepts a format string to format playback time
screenshot: make it possible to format playback time in various ways
mplayer: attempt to skip playlist entries which can't be played

This is for situations when repeated attempts at playing a playlist
entry failed, and playlist navigation becomes impossible due to that.
For example, it wasn't possible to skip backwards past an unplayable
playlist entry:

    mpv file1.mkv doesntexist.mkv file3.mkv

You couldn't skip back to file1.mkv from file3.mkv. When running a
single "playlist_prev" command, doesntexist.mkv would be played, which
would fail to load. As reaction to the failure to load it, the next file
would be played, which is file3.mkv.

To make this even worse, the file could successfully load, but run only
for a split second. So just loading successfully isn't good enough.

Attempt to solve this by marking problematic playlist entries as failed,
and by having playlist_prev skip past such playlist entries. We define
failure as not being able to play more than 3 seconds (or failing to
initialize to begin with). (The 3 seconds are in real time, not file
duration.)

"playlist_prev force" still exhibits the old behavior.

Additionally, use the same mechanism to prevent pointless infinite
reloading if none of the files on the playlist exist. (See github issue

All in all, this is a heuristic, and later adjustments might be
necessary.

Note: forward skips (playlist_next) are not affected at all. (Except for
the interaction with --loop.)
screenshot: change %w format to be more like %t

Instead of containing a format string within %w{...}, simply allow %w
to specify one item of a time format string. This is simpler, more like
other format specifiers (%t),  and probably easier to use too.
manpage: remove version and date fields

These would have to be updated manually all the time. Replacing them
automatically would be possible, but additional work, and would force
regeneration of the manpage way too often.

We decided that we don't need these fields.
Add mpv.desktop, let Makefile install the desktop file and the icons

The mpv.desktop file is taken from the Arch package [1]. It appears to
be based on the mplayer2 git mplayer.desktop file (e.g. very similar
MimeType field), with minor modifications applied by Arch package
maintainers.

Note that for now, this doesn't show a terminal (Terminal=false), which
might not always be ideal. For example, if the file is audio only, or
if VO initialization fails for some reason, mpv will run in the
background and play audio without showing a window. But users prefer
running it without terminal, and don't want to play audio files with
it.

Maybe a --force-window option will be added in the future, which would
always create a VO window, and compensate for these issues.

[1] https://aur.archlinux.org/packages/mpv-git/
manpage: remove bogus space in example usage
command: force video refresh when changing aspect

Pausing the player and changing the aspect would leave the VO without a
frame to display.
demux_mkv: don't add too many subtitle packets during seeking

In insane files with a very huge number of subtitle events, and if the
--demuxer-mkv-subtitle-preroll option is given, seeking can still
overflow the packet queue. Normally, the subtitle_preroll variable
specifies the maximum number of packets that can be added. But once this
number is reached, the normal seeking behavior is enabled, which will
add all subtitle packets with the right timestamps to the packet queue.
At this point the next video keyframe can still be quite far away, with
enough subtitle packets on the way to overflow the packet queue.

Fix this by always setting an upper limit of subtitle packets read
during seeking. This should provide additional robustness even if the
preroll option is not used.

This means that even with normal seeking, at most 500 subtitle packets
are demuxed. Packets after that are discarded.

One slightly questionable aspect of this commit is that subtitle_preroll
is never reset in audio-only mode, but that is probably ok.
mplayer: read subtitle packets as soon as possible

Call update_subtitles() on every iteration of the playloop, so that
subtitle packets are read as soon as possible, instead of every time a
video frame is displayed. This helps in case the packet queue is swamped
with subtitle packets, which can happen with certain insane mkv files.
The change will simply cause the subtitle queue to be emptied on each
playloop iteration.

The timestamps update_subtitles() uses for display are the same before
and after this commit. (Important for files which have subtitle packets
with timestamps or duration not set.)
gl_common: signal to GL backend whether we are probing

This is supposed to reduce the amount of useless error messages shown
during initialization of vo_opengl. If multiple backends are compiled,
usually only one of them will work. For example, on Linux both X and
Wayland backends can be compiled, but usually either Wayland or X is
running. Then, if Wayland is not running, but X is, trying to initialize
the Wayland backend should not spam the terminal with error messages.

Signed-off-by: Andreas Sinz <andreas.sinz@aon.at>
gl_common: add wayland backend before x11 backend