Added some shortcuts to get data from the Resource Manager.

Simple stuff, to spare some keystrokes and foster shorter lines.
Fixed some typos in documentation comments in config.d.
Fixed documentation copy & paste error in canned_updaters.d.
Added methods to Bitmap that allow to draw it.

Prior to this, it was necessay to resort to the Allegro API to draw
FewDee Bitmaps.

(Christmas commit! :-))