Refactor Motion UI

[soumak77]

ZURB has decoupled the Motion UI logic into its own library. Since Motion UI is used by Foundation for Sites, I think it would be safe to assume the library will be maintained as needed. Worst case we just create a new version of the library under Base Apps as we have for the other unmaintained libraries from ZURB.

Only the SCSS code will be used from Motion UI. Angular Base Apps will still provide the integration with angular instead of using the jQuery support provided by Motion UI.

The class naming convention for the motion css classes has changed from camelCasing to kebob-casing in ZURB's Motion UI. Since the library provides mixins, Angular Base Apps could keep the camelCasing naming convention, but I would prefer to stick to the same convention as Motion UI. The support for Motion UI classes can be added in a dot release, but deprecation of the current naming convention will need to wait for a major release.