audio: restore old speed change behavior

Don't attempt to resync after speed changes. Note that most other cases
of audio reinit (like switching tracks etc.) still resync, but other
code paths take care of setting the audio_status accordingly.

This restores the old behavior of not trying to fix audio desync, which
was probably changed with commit 261506e3.

Note that the code as of now wasn't even entirely correct, since the A/V
sync values are slightly shifted. The dsync depends on the audio buffer
size, so a larger buffer size will show more extreme desync. Also see
mplayer2 commit 213a224e, which should fixed this - it was not merged
into mpv, because it disabled audio for too long, resulting in a worse
user experience. This is similar to the issue this commit attempts to
fix.

Fixes: #1042 (probably)
CC: @mpv-player-stable
player: fix quit handling when seeking past EOF while paused

The player didn't quit when seeking past EOF in audio-only mode while
paused. The only case when we don't want to quit is when the last video
frame is displayed while paused.

This logic was probably broken a while ago, but I'm not exactly sure.

CC: @mpv-player/stable

Conflicts:
	player/playloop.c
x11: when using --wid, inherit event flags from parent window

When embedding a X window, it's hard to control whether it receives
mouse/keyboard input or not. It seems the X protocol itself makes this
hard (basically due to the outdated design mismatching with modern
toolkits), and we have to take care of these things explicitly.

Simply do this by manually querying and using the parent window event
flags.

This restores some MPlayer behavior (it doesn't add back exactly the
same code, but it's very similar).

This probably has some potential to interfere with libmpv embedding, so
bump the client API minor.

CC: @mpv-player/stable (if applied, client-api-changes.rst has to be
    adjusted to include the 0.5.2 release)
audio/out: prevent burning CPU when seeking while paused

The audio/video sync code in player/audio.c calls ao_reset() each time
audio decoding is entered, but the player is paused, and there would be
more than 1 sample to skip to make audio start match with video start.
This caused a wakeup feedback loop with push.c.

CC: @mpv-player/stable
playlist: don't add the base path twice

Loading a playlist with --playlist from a sub-directory added the
playlist's base path twice: one time in the playlist demuxer, and then
again in playlist_parse_file(). The latter function is used only for
--playlist, so it worked when loading the playlist directly.

(This is probably a mess-up when the MPlayer playlist parsers were
replaced with newer code.)

CC: @mpv-player/stable
man: fix a whole bunch of typos

Conflicts:
	DOCS/man/input.rst
	DOCS/man/options.rst
gl_wayland: fix crash after eglInitialze failed

Only execute most of the opengl termination procedure if we actually have an
egl context.