DynamicActionBar and State Tweaks

Closes #122, Re: #124 #126

- Adds icons for switching between vendor and client
- Simplifies ActionBar layout to use ImageViews without source drawables
- Updates the channels to take handlers (instead of throwing exceptions) on publish
- Adds AsyncStateUtil for easier asynchronous activity switching
- Simplified DynamicActionBar API and added convenience methods for common tasks
- Refactored activities to use the refactored DynamicActionBar
Merge pull request #141 from steffanc/122-action-bar

DynamicActionBar and State Tweaks