manpage: correct the definition of full range video
video: honor the video's colormatrix and color range flags

If either of them is not defined, the old behavior is used:
- the colormatrix is guessed based on resolution.
- the color range is assumed to be tv aka limited range.
Adjust ffmpeg/libav #includes to work with recent upstream changes

The <libavutil/avutil.h> stopped including <libavutil/common.h>
recursively in recent ffmpeg/libav git revisions. As a result, some
files no longer got needed definitions, causing a build failure.
Modify #include lines in various files to fix build with the latest
versions of ffmpeg/libav headers.
osd_libass: fix displaying empty text, fix API usage

If empty text is rendered, the bounding box is empty. Instead of
continuing with a bogus bounding box that would result in garbage
being rendered on screen, make the OSD image invisible.

This happened when playing demuxer SRT subtitles (e.g. SRT embedded in
MKV) with -no-ass at the moment a subtitle line disappeared.

Unrelated to this issue, fix libass API usage. Delete the event with
libass_flush_events(), instead of trying to reuse the previous event.

Based on a patch by uau.
img_format, m_option: make image format name list globally available

And add functions for converting them from/to the name string.
vf_dlopen: add a generic filter to load external filters

Usage: -vf dlopen=filename.so:args...

Examples of such filters are provided in TOOLS/vf_dlopen/
manpage: fix various typos
manpage: don't mention nonexistent VOs, command line switches, etc.

Very likely doesn't remove all outdated things.
manpage: mention that videos' colormatrix and color range flags are honored
manpage: fix ambiguous statement about --(no-)keepaspect
manpage: update example of the status line
manpage: update the list of available screenshot formats

Also update the default value of --screenshot-jpeg-quality
manpage: --screenshot-template: update %n, add %{prop}

Explanation of %{prop} taken from the commit message of commit
12c44610ad6963bb58c01cc4415cc7befef386e1 (screenshot: make screenshot
filenames configurable).
manpage: update default value of --softvol-max
manpage: update default jpeg quality for vo_image
input: add ability to disable all default bindings for an input section

Add a flags parameter to mp_input_set_section(). Add a flag that defines
whether bindings in the default section are used or not. This is useful
for special functionality, where the normal key bindings may have
unwanted effects.

For example, it shouldn't be possible to seek during encoding. However,
you want to be able to cancel the encoding process gracefully. For that
purpose, the "encode" section of input.conf could be made exclusive:

    mp_input_set_section(mpctx->input, "encode", MP_INPUT_NO_DEFAULT_SECTION);

And input.conf could contain this definition:

    RIGHT seek 10
    q {encode} quit

Then only the key "q" would be bound during encoding.
configure: restore DVB support

The code defining CONFIG_DVB[IN] was accidentally removed some time ago.
configure: minor improvement to summary output

Remove printing VO modules that were removed earlier, but were enabled
by configure tests that are still needed.

Print "libavcodecs" with the "Codecs: " output.
configure: disable optimization if --enable-debug is used

Enabling optimization _still_ causes annoyances when using a debugger,
and it increaes compilation times too.

Now --enable-debug basically replaces the -O2 flag with -g.
Merge remote-tracking branch 'cantabile/manpage_fixes'