CRAFTERCMS-184: Enable moving and creation of components from the ICE toolbar

- Remove dependendency on method from common-api (causes race condition)
- Improve styles for new components
- Fix FF bug related to getComputedStyle
CRAFTERCMS-184: Fix the inheritance of styles when moving components

Fix the inheritance of styles when the drop zones are enabled.
Merge remote-tracking branch 'david/master'
CRAFTERCMS-179: 'Change Template' should not be available on empty folders

The 'Change Template' option in the context menu (in the site dropdown)
should not show up if folders are empty in the Components and Pages
sections.
CRAFTERCMS-179: 'Change Template' should not be available to folders