Skincolor Fixes (#109, #115)

• k_color function suite: Promote skincolor ID datatype to fix support for more than 255 skincolors (resolves #109 (closed))
• Minimap directioning dot will use the correct skincolor even when set up for alternate remappable indices (resolves #115 (closed))
• Fix typo that was corrupting Spray Can cache when freeslotting custom skincolours (from both SOC and Lua, no tracking reference)