Support adding new SIDC and exclusion of SIDC
Support adding new SIDC and exclusion of SIDC

This is part of an ongoing work to break milsymbol into several modules
so that you only need to load what you want to use. It is also
preparing for the possibility of adding more parts of the tactical
symbols in the future.

spatialillusions/milsymbol,okwolf/milsymbol,okwolf/milsymbol