project: gwt w/json requires vtm-extras
gwt: geojson tilesource
gwt: test map layers
fixup: VectorTileRenderer - need to enable depthmask for clear
fixup: VectorTileLayer dup method
theme: fix, only add casing when core is rendered
fixup: GeoJsonTileDecoder, no need for double buffering
cleanup: emu VectorTileLayer
unset overdraw color on vector overlays
theme: fix river width below zoom=12
add getter for UrlTileSource.getUrl()
move BitmapTileLayer to layer.tile.buitmap

- extract BitmapTileLoader
- bring back GWT BitmapTileLayer to life
set default max/min zoom
more OsmLanduseJsonTileSource tag mappigs
fix: add working default for VectorTileLoader.filterTags()
add VectorTileLayer constructor with TileSource
android-example: use VectorTileLayer instead of OsmTileLayer