### Problem description
Older image format use to store color values in a small lookup table so
that the image could simply store an index to the table. The pattern
language is not designed to handle this sort of operation which makes
this extension necessary to be able to visualize images of this type.
### Implementation description
The changes add an optional parameter to the bitmap visualizer which
holds the color lookup table. If the image contains values that are
outside the range of possible colors then the first color in the map is
chosen. The dimensions of the image can be equal to or smaller than
rows*columns depending on how the indices to the color map are stored.
For example, you can use 4 bit indices which would make the image half
the size (in bytes) but that limits the number of colors to 16. To store
colors in sizes larger than one byte use an array of the appropriate
sized integers.
### Screenshots
