[Implemented] PB_Ignore for ResizeImage

[jamirokwai]

Dear PB-Team,

I'd like to see the possibility of using #PB_Ignore for ResizeImage() also.
So you could load an image e.g. 200x160 and resize it to 100x160 with ResizeImage(0,100,#PB_Ignore).

[AND51]

Yeah, this would improve readability of source codes.