input: fix stack overflow when checking for abort cmd

This can happen when the input stream is somehow blocking on network,
and the user still send input in one way or another, and one of the
commands is a compound command ("cmd a ; cmd b").
manpage: fix vf_scale options
demux_lavf: one more hack for mp3 from network

mp3 has a hack lowering the probescore for format detection. This is
because detecting mp3s is hard due to their nature, and the fact that
ID3v2 tags are sometimes several megabytes big.

When playing mp3 from network, the mime-type is usually set, and that
matches the format hack entry meant for webradios, overriding the normal
mp3 entry. This can lead to network mp3s not being detected. Lower the
network case to the same probescore as on-disk mp3s. The difference is
that for network mp3s, we don't load the full probe-buffer, and we lower
the amount of audio the demuxer will read to collect data on opening
(0.5 seconds instead of typically 5 seconds).
mixer: don't restore volume with different --softvol-max settings

Changing --softvol-max and then resuming would change the volume level
on resume to something different than the original volume. This is
because the user volume setting is always between 0-100, and 100
corresponds to --softvol-max gain.

Avoid that changing -softvol-max and resuming an older file could lead
to a too loud volume level by refusing to restore if --softvol-max
changed.
Fix bogus copyright text

This file was copied from gl_hwdec_vaglx.c to have a basic skeleton, but
no actual code is left from it.
sub: fix undefined behavior in ASS color calculation

This might shift bits into the sign, which is undefined behavior. Making
the right operand unsigned was supposed to help with this, but it seems
it did nothing, and C99 makes the result type dependent on the left
operand only.
sub: fix undefined behavior in ASS color calculation (2)

Same problem as previous commit, fix by using the MP_ASS_RGBA() macro.
x11: fix potentially unaligned access in icon loader

Tried to load a 32 bit value by dereferencing a uint32_t pointer, but
the pointer is not guaranteed to be aligned, not even in practice.
old-makefile: add a missing source directory

Fixes "make clean".
player: don't complain on too long filenames

mpv supports per-file config files, basically filename+".conf". We use
a static buffer for the new filename, and if that buffer is too small,
we print a warning. This is confusing for e.g. long URLs, so just hide
the warning by default.

Why not dynamically allocate the buffer? Who cares.
build: removed undefined behavior from PVR check

This shouldn't matter, but it's probably better if the code to check is
valid - otherwise an extremely clever compiler might fail to compile it,
and the feature would be misdetected. (Probably.)

Found by cppcheck.
player: don't assign "false" to pointer

This is legal in theory. "false" expand to 0, and 0 is a valid pointer
value. But I guess this was not really intended.

Found by cppcheck.
manpage: update --playlist entry
build: fix OpenBSD DVD/CDROM device names

Closes #781.
wayland: fix typo

So long in the code without me noticing. Embarassing!
README: describe release cycle
Fix the build on OpenBSD and FreeBSD

Without this change, the compiler uses by default the "talloc.h" file
installed by the package libtalloc within /usr/local/include. Found and
tested on OpenBSD but FreeBSD has the same patch on its ports tree.
vo_vaapi: don't redraw twice

After VOCTRL_REDRAW_FRAME, flip_page is called, which renders the frame.
The current code rendered the frame twice; drop the redundant call.
build: "tv-v4l2" needs "tv"

Fixes #795.
x11: fix a warning with --disable-xext

Signed-off-by: wm4 <wm4@nowhere>