New UI skeleton

Change view model to navigation based view controller
Sign in view, meetings view and new, buzz view controller, New buzz
view controller
Merge branch 'master' of https://github.com/scotasaurus/buzzer

Conflicts:
	BuzzeriOS/Buzzer.xcodeproj/project.pbxproj
Revert "Merge branch 'master' of https://github.com/scotasaurus/buzzer"

This reverts commit 8fbc7e53f2afb68bf0b66851725ee1ee75c73fdc, reversing
changes made to 951fbd55564259b40b7569db424c3d305eccd405.
User file
Merge branch 'master' of https://github.com/scotasaurus/buzzer

Conflicts:
	BuzzeriOS/Buzzer.xcodeproj/project.pbxproj