fixed misc/stats.c:399: warning: comparison between signed and unsigned in function '__stats_TimerClean'

Based on usage of i_id, other stats_* functions and my opinion i_id should be unsigned int instead of int, but I might be missing the bigger picture related to changing public APIs. Please, let me know how to correctly deal with such warnings.

Caution: other pieces of code may have been randomly deleted in
920692ff

Properly initialize psz_name in PrintObject(). Fixes a warning: "Conditional jump or move depends on uninitialised values"

When demuxing with ffmpeg, set the VLC block I frame flag when it is marked as such by lavf. This fixes flv restreaming without transcoding.

Simple Preferences - Audio: Don't build widget not useful for your platform instead of hiding them. Will remove some weirdness on windows for resizing.

If you wan a better decription of each module in this file please add it.

The problem came from my misreading of the API
This commit also fix potential misunderstanding by simplifying it further