docs: MatchingCacheKey
move TagFilter stuff to OsmTileLayer
refactor: TileLoader.createLoader()
get theme from VectorTileLayer, instead of setting it on Loader
refactor: MapTile hold generic TileData - Testing
start TileLoaderHook:

- only create ExtrusionLayers when a BuildingLayer is attached
use Object as ID for TileData
docs: MapTile
PathLayer - inner class should be static
insert new hooks at front
move Text/Symbol handling to LabelTileLoaderHook
move Label/Symbol data from MapTile to LabelTileData
let TileLoaderHook stop further processing

- return false when no other loader hook should process
  the current element
add TileLoaderProcessHook to intercept MapElement processing
cleanup: Tag
name clipMode magic-numbers, docs
move cast into addVertex
add GwtInput to disable key callbacks on Document
add color conversion for rgb-hsv and parser for rgba() strings

parse rgb()/rgba() color strings
cleanup AwtBitmap