We might need to generate Opus headers without actually encoding anything

Was regression with that tricky one:
http://streams.videolan.org/issues/10981/6.mp4

This overrides any autotools site configuration.

CVE-2014-3466

things that does not belong to libmp4

They are several complaints for nonworking functionality with this
mode, because not every option combination is supported yet.

Additionally, the initial reason for this commit, namely grey
bars in fullscreen, is fixed by a workaround for 2.2.

This reverts commit 72b60566.

Conflicts:
	modules/gui/macosx/macosx.m

Fixes #2575, #11514

There was the missing ref clock assertion after SET_GROUP_PCR because
that group had no active es.

Unsure if that's the best way to find all es associated to a PMT/group/program

Francois

Adds a data order driven demuxer instead of trying
to rearrange seek order. Re-enables fragmented
files if fast-seekable.

So we can stop probing at some point.

The code no longer compiles with older versions anyway.