Added empty aggregate function and handling
Shown variable handling for aggregations
Added aggregate SPARQL string creation

Also moved aggregate array to a factory variable
Initial addition of aggregates.
Merge branch 'aggregateTranslate' into feature/r4-3-aggregate-functions

Conflicts:
	app/js/config.js
Adjusted translation to get it working.
Fixed aliases for aggregated properties
fixed aliases for aggregate properties even more

There was a problem with a missing distinction between Datatype and
Object properties, as the aliases of those are handled differently
(prefix for Datatypes)
Minor fixes with alias (made functions private)
Added possibility to remove Aggregate functions.
Merge branch 'feature/r4-3-aggregate-functions' into develop

Conflicts:
	app/js/app.js