0.9-alpha.2

The 0.9-alpha.x.y series will mirror RAC 4 pre-releases while still allowing new development

This release targets RAC 4.0-alpha.2

• [added] Added numerous UIKit extensions (#54, thanks @avalanched!)
• [added] Made several Cocoa extensions public (#42, thanks @ikesyo!)
• [fixed] Compiler warning around StaticString (#43, thanks @ikesyo!)