improve the tests for the drop handler
merge in trunk, fixing conflicts
fix tests and bug
fix lint
Update css to correct FF tabview layout
Merge pull request #131 from mitechie/fix-ff-tabs

To QA: 

See the bug https://bugs.launchpad.net/juju-gui/+bug/1277148

Test out the tabs on charms and bundles in Firefox and IE.
fix test
Merge pull request #129 from benji-york/more-drop-handler-tests