Dev popup

This pull request has for main purpose to add a popup module with a directive and service.

Why a directive ?

Because it centralize the HTML created for popups. Actually the directive use transclusion so it's a wrapper of some HTML content. 

You can test it from the accordion when you open Import WMS or KML component.

The directive is used like this:

`<div ga-popup="importKmlPopupShown"  ga-popup-options="{title:'import_kml'}">
</div>`


Why a popup service?  

Because we need to open popups dynamically to  display layer informations or result of GetFeaureInfo.
This service add dynamically a popup directive in the HTML tree. 

You can test the service displaying a KML file ( http://dl.dropbox.com/u/44486020/swisstopo.kml ) then click on features displayed.
 
You can use the service like this:  

   gaPopup.create( { title: "my popup", content:"\<div\>my html content\</div\>"}).open(scope);




Demo URL:

http://mf-geoadmin30t.bgdi.admin.ch/branch/dev_popup/prod/?lang=fr&X=190000.00&Y=660000.00&zoom=1&topic=ech&bgLayer=ch.swisstopo.pixelkarte-farbe