compiler/libec: (#1029) Fixed crash serializing null class instances
ecere/gfx/Bitmap: Fixed loading from file at current position
- Previously broken by 61f70093a82be11336467c6e3f177f1c911fa50d
- Acovel relied on this behavior to load pictures from ID3 tags
ecere/gfx/pcx: Fixed crashes guessing images as PCX