Add mech_key field to MechDesign
Allow blank values for BV / Cost as Omni Base Chassis layouts don't have these
Add skeleton classes for Equipment / Mounting
Add a set_slots() function for Mounting
Add 'No Location' location for equipment that does not use a critical slot.
Add omni_loadout and support multiple loadouts from the same file
Add some basic decorators for input validation
Add Validation Decorators to Mech Import program
Allow Numbers in Basic String
Add dictionaries for mapping SSW locations to StableManager location codes
Fix an incorrect location code
Merge remote-tracking branch 'origin/master'