2.0.0

I do realize I need to get better at versioning this... The changes that occurred since v1.0.0 include:

Manipulators/Switches

• (Multiple) changes to how switches are interfaced with
• Support passing existing 'state' datarefs that will automatically be updated as the switch moves
• Remove redundant spring flag from sw_new2()
• Fix for switches with no descriptions for their commands
• Fix at least one crash

Persistence System

• Add a (still WIP) persistence system, adapted from the DA40

Other

• Include X-Plane SDK v4.3.0
• Various refactorings & improvements

1.0.0

Initial "stable" release