Save/LoadProfiles

ScreenProfileLoad and ScreenProfileSave do nothing except use their own
lua methods to run GameState functions. Those functions might as well be
available as GameState methods.
luadocs

added lua documentation
Merge pull request #110 from sigatrev/Save/LoadProfile

Expose Save/load profile to Lua. This deprecates ScreenProfile{Load,Save} completely, but those are going to be left in until post-5.0