New toolbar style.

This includes:

- Button label is now hidden by default. Shows as tooltip on hover.
- No "button"-look any more for toolbar buttons.
- Overall slimmer toolbar.
- New link, button and input focus style.
Put an insert element button between and above each element.

Before we had one button that always appends the element at the end of the list.
Now the user can choose where to add the element.
Adds feature spec for admin/element trashing.
Removes temporary phantomjs fix for Mavericks. Refs #554
Removes db connection sharing between threads and adds database_cleaner

This runs much more stable, also when running in different environments like slow CI servers.