multi_efficiency_parts

Adds support for multiple efficiency parts. part efficiency can now
accept more than one type of part at a time. Parts are separated by semicolon.
Example: efficiencyPart = MKS_HabDome;OKS_HabRing;WBI_IMEM
This allows for situations where, for example, the same Kolony module can be used in orbit or on the ground, but with efficiency parts built specifically for space or ground environments.

Testing done:
- no efficiency parts
- one efficiency part
- two parts of the same type
- three different efficiency parts