object: use form.$pristine to disable save button (#123)
controllers: extract EditModalCtrl

This collects the logic for the edit-modal in a single controller.
Doing so simplifies the ObjectCtrl and has the benefit that the
controller can operate directly on the scope used by the modal.

Before, the modal was using a child scope of the scope that we
configured -- this meant that forms and fields published on the scope
by ngModel and ngForm weren't available to us.
edit-modal: enable save button after change (fixes #123)
edit-modal: use real buttons instead of a elements

This allows us to test the enabled/disabled state of the elements.
While <a class="btn">...</a> renders a nice button, running

  $('a.btn').isEnabled()

in Protractor always return true, even if a ng-disabled directive has
disabled the link. Using a button element instead works fine.
partials: add type="button" to all button elements

Without this, the button is technically a submit button.
edit-modal: simplify tests slightly
Merge pull request #124 from mgeisler/allow-saving-after-change

Allow saving after change