*WORK IN PROGRES*   Dev time selector

This PR add 2 components:

- a generic slider component copied  from this one: https://github.com/prajwalkman/angular-slider

- and the TimeSelector component, this component display a select box on mobile (or a slider on desktop) when a layer timeEnabled is added to the map.

WARNING: Until we can update layer params in OL3, this component doesn't affect rendering of layers.

You can test the component here : 
   
    http://mf-geoadmin30t.bgdi.admin.ch/branch/dev_time_selector/prod/?lang=fr&topic=blw&bgLayer=ch.swisstopo.pixelkarte-farbe&X=190000.00&Y=660000.00&zoom=1
 
Open the catalog tree and add the layer "Cartes voyage dans le temps" ("Karten - Zeitreise")