Make saved / needs saving state more obvious in the admin

[clarkwinkelmann]

Currently when you edit a field, nothing tells you if you need saving. The save button itself is called "edit field" which is very unintuitive. The button should really be disabled until you make a change.

When creating the field types I added an autosave feature when you edit the dropdown type so that if you believe "add" saves the field, well it does... But you should actually be hitting "edit field" to have the new options list saved.

[clarkwinkelmann]

The buttons have been renamed in the 0.3.x releases to make them a bit more explanatory, but there's still no "disabled" style indicating that everything is saved.