Add Icon Collection to data modell

[dhaeb]

• icons are partly global (pre definied ones) and partly user definied
• lets add a global collection for the global ones and include all user defined icons into the user document
• reference using an ObjectId from global / self def icons to the tags

[TBoonX]

Use free icon sets.
There are some types of sets:
The first is more a set of templates for icons. So you can change the color and the size if you want. For this we have to create an identifier which holds the icon id and the style information. Example: http://fortawesome.github.io/Font-Awesome/
The second is to just download some and save them on the server, so we only have an identifier in the Tag object.. There are hundret of sites, one example: http://www.flaticon.com/packs/mean-icons

So yeahr I like to download some free icons, save them on the server, make a list of their names (manually or dynamic per service) and give the list to the app. So just a simple reference in the Tag object.