Added a transparent line fill from an XY offset function

|SOURCE|
[Video]
* FillRasterLineTransparentXY added to copy the colour data to an X, Y
  specified offset
Added a function to load palette data from a file
Removed all palette data references which reside in a bitmap file

|SOURCE|
[Font]
* Stubbed-out a function for loading fonts from a file
[Image]
* Removed all image-based palette code
[Video]
* Added LoadPaletteData to reference palette data from a file
[Main]
* Using the external palette data file for setting the palette

|CONTENT|
[PALETTE.PAL]
* Generated from the font bitmap (using the Quake palette)