Bumped version to 0.2-SNAPSHOT. Decreased target compiler level. Modified annotations.

- @ExpectedFailureProfile:
  * Renamed internal enum FailureMode to Kind
  * Added/restored default Transactional.UNKNOWN on transactional property
- @ExpectedPerformanceProfile:
  * Renamed internal enum PerformanceCharacteristic to Kind
- @HasSideEffects now has new property javax.annotation.meta.When when()
- Target compiler level decreased to 1.5, for those poor souls that still
  have to sit on that.
Heavily modified README.md (grammar, rewrites, added examples)