Fixed a few warnings. Rev: src/modules/Image/blit.c:1.46 Rev: src/modules/Image/colortable.c:1.90 Rev: src/modules/Image/colortable.h:1.22 Rev: src/modules/Image/colortable_lookup.h:1.12 Rev: src/modules/Image/encodings/gif.c:1.56 Rev: src/modules/Image/encodings/iff.c:1.8 Rev: src/modules/Image/encodings/ilbm.c:1.18 Rev: src/modules/Image/encodings/png.c:1.37 Rev: src/modules/Image/encodings/psd.c:1.22 Rev: src/modules/Image/encodings/ras.c:1.10 Rev: src/modules/Image/encodings/x.c:1.30 Rev: src/modules/Image/font.c:1.62 Rev: src/modules/Image/matrix.c:1.28 Rev: src/modules/Image/pattern.c:1.22