Qt: InputManager: don't enforce lower bound after a seek

Should fix problems like #2243.
After a seek, the updated position could be the keyframe position
choosen by demux, and then lower than A.
demux: asf: fix overflow in seek
demux: asf: fix variable length reading.

While current spec doesn't make use of > WORD sizes,
the code was following the spec and reading variable length
up to 3 bytes precision and writing it to a (int *)...
This patch fixes signedness too.
macosx: fix crash when closing video window without decorations
macosx: fix issue which caused automatic video resizing even if disabled

close #9864
demux: asf: add fake root guid for debugging
demux: asf: enforce root object boundary (fix #9441)

Seems some encoder reuses previous memory area for junk sections.
Fix read of unitialized variable (cid #1125395)

Even if should not have any impact during execution.
ogg: fix type conversion (cid #1125392 and #1125393)
asx: fix many memory leaks (and cid #1109641)
auhal: fix crash on error paths for stream format change

ref #9957