Abstracting AppBar Layout implementations into new _Layouts file.
"custom" layout AppBar uses private _AppBarBaseLayout class.
"commands" layout AppBar uses  private _AppBarCommandsLayout class, which is derived from _AppBarBaseLayout.

Added new AppBar unit tests and fixed 2 Failing Menu/MenuCommand tests in WWA
Remove unused configuration variables.
Add the AMD sandwhich to all base.js files.
Update amd.js to handle flexible paths.
Add define around all UI modules.
Remove unnecessary references to global.
Style cleanup.
Re-enable file name checking for source files built with requirejs.
Add documentation
Fix build break.
Merge in changes from Jesse.