Integrated Font Awesome

Added Font Awesome to mockup.
  - Added new package dependency
  - Created new bootstrap.less (required for awesome)
  - plone.app.widgets does not build with font-awesome
  - mockup builds with font awesome
  - plone.app.toolbar builds with font-awesome

Font Awesome files are copied to build/toolbar-webfont.* , I chose this naming so that the same copy command could be used to update plone.app.toolbar. plone.app.toolbar also needs some modification:
   - Remove resource plone.app.toolbar.png
   - Add resources for fonts:
        plone.app.toolbar.ttf, plone.app.toolbar.woff etc.

I have the changes required on plone.app.toolbar available locally, can supply those also.