IVA improvements

[Capkirk123]

Some general improvements for ROCapsules IVAs.

• Mercury: Switch to more detailed FASA interior
• Gemini: Add missing props from interior
• Apollo: Switch to realistic DECQ interior rather than stockalike DECQ interior
• LEM: Switch to realistic DECQ interior rather than stockalike DECQ interior
• Apollo BIII+: Add additional seats to interior

resolves #102
resolves #183

[lancisman]

Possible issue? Trying to switch to the regular Apollo capsule, gives an error in the console and log, saying, "Cannot find InternalPart 'ApolloCM_Internal'". Then a line lower has the error "Cannot add an InternalPart: Cannot find internal of name 'ApolloCM_Internal'", the block III variant, which appears to use the same IVA with 2 more seats, is fine. Also noticed a small typo in a comment in "Internal_ApolloBIII.cfg", says "//5-man Apollo was pretty cramped. We'll but them between and below existing seats, and just accept a little clipping", the "but" in the second sentence should say "put".