VBNavigationController

Re: #13

- Initial add of basic navigation controller and assets
- Toggle selected state
- Toolbar sliding
- Proper menu sliding state tracking
- Additional view nibs
- Refactoring and use of existing VBColor
- Category in it's own file
- Wire in caption controller and turn off status bar.
- Nib files in project file
- Navigation menu protocol and menu state classes to go with NIBs
- Wiring together navigation controller states with stubs.
- Cosmetic fixes
Merge pull request #49 from azoff/13-feature-navigation-controller

13 feature navigation controller