LibDraw: Start work on a GIF decoder (not yet functional!)

Here comes the first part of a GIF decoder. It decodes up to the point
of gathering all the LZW-compressed data. The next step is to implement
decompression, and then turn the decompressed data into a bitmap using
the color maps, etc.

Libraries/LibDraw/Makefile

@@ -8,6 +8,7 @@ OBJS = \
     GraphicsBitmap.o \
     Painter.o \
     PNGLoader.o \
+    GIFLoader.o \
     ImageDecoder.o \
     Rect.o \
     StylePainter.o \