Kothic Json parser for vector data tiles

During GSoC 2012 for vector tile rendering, Kothic's servers json tiles
(hosted on http://osmosnimki.ru/vtile/ - please don't use it
heavily-loaded projects for now) have been used while OpenStreetMap
finishes building its own data tile server. These Kothic tiles have a
very similar format
(https://github.com/kothic/kothic-js/wiki/Tiles-format) to the ones that
OSM will have.

A problem was found with QScriptValue for multidimensional arrays. When
having for example [[20,10],[20,30].[30,30]] if we extract the property
it will flatten to 20,10,20,30,30,30. This parser doesn't create
separate inner geometries because of this. It will connect the inner
geometry with its outer.

It will set the geometries name and style according to what
OsmVisualCategory generates for the parsed tags.

This parser creates a GeoDataDocument with all the extracted data.
REVIEW: 106008