New meta in LDConfig for default category icon in editors

[Orion Pobursky]

I'd do:

Code:

!MASCOT CATEGORY <Category> DESCRIPTION <description> PART <Matrix> <Part>

Example:
!MASCOT CATEGORY Plate DESCRIPTION Plates PART 1 0 0 0 1 0 0 0 1 part.dat

Reason:
Some Categories are 2 words. This makes parsing much easier.