Fixed potential sscanf buffer overflow in :

Fixed potential sscanf buffer overflow in :
 - ParseMicroDvd
 - ParseSubRip
 - ParseSubViewer
 - ParseSSA
 (Reported by Michal Luczaj)
Fixed memory leak in ParseSSA
Fixed invalid memory access in
 - ParseSSA
 - ParseVplayer
Improve a bit MPL2 support (remove italic format + initial space on
first subtitle)
All: simplify
     check malloc (what a boring thing)
	 do not allocate up to 160ko on the stack
( I have tested all formats with a small sample but please test/report any
regression on your files. )