Remove breadcrumb module
Move breadcrumbs into YdtdFrontend::Engine

Includes:

 - breadcrumb helper
 - new shared view
 - updates to scss
Ensure button height same as a.button
Use same margins
No need to resize fonts for portrait tables
Add flash view and helper to YdtdFrontend
Use $norm padding
Tidy up
Remove page classes from body
Rename .application--flash to .application--flash-container
Split out responsive styles for .application--content and .application--flash-container