+ ajax handler backoffice

Ajoute un handler ajax configurable avec un markup simple.
Tous les champs contenus dans "ajaxhandler" ainsi que les attributs "data-*" seront postés vers "data-url". Ex :

	<a href="#" class="btn btn-mini" data-ajaxhandler="#ajaxhandler">Ajouter</a>
	<div id="ajaxhandler" data-type="2" data-url="/url" data-yourmom="fat" style="display: none">
		<select name="foo">
			<option value="bar">Bar</option>
			<option value="foobar">Foobar</option>
		</select>
		<input name="baz" />

		<a href="#" class="btn btn-mini" data-action="go" >Valider</a>
		<a href="#" class="btn btn-mini" data-action="cancel" >Annuler</a>
	</div>
Merge branch 'master' of github.com:kappuccino/kodeine

Conflicts:
	module/core/ui/js/common.js