(PhVideoEngine) Fix new/delete operator mismatch

_rgb was allocated with new[] and freed with delete instead of
delete[].
(PhStripDoc) Fix doc contents leak.

Clearing a QList does not free its contents.
(PhLtcReader\Writer) Delete the encoder/decoder in destructor
(PhStripDoc) Fix DOM leak
(PhVideoEngine) Fix AvFrame leak
(PhVideoEngine) Fix new/delete operator mismatch

_rgb was allocated with new[] and freed with delete instead of
delete[].
Merge pull request #271 from tlecomte/tlOtherLeaks

Tl other leaks