Fix liveBlur and cornerRadius, close #63
Version bump (1.8.4)
Allow setting a custom alpha value for the background.
Merge pull request #64 from domhof/feature/custom_background_alpha

Allow setting a custom alpha value for the background.
Rename backgroundViewAlpha -> backgroundAlpha
Refactor self init
Refactor init methods
Minor refactoring
Minor refactoring
Refactor REMenuItem
Merge branch 'master' of github.com:snown/REMenu into development