fix: gwt LwHttp emulation
enable logging for gwt
add TileGridLayer wrapper for GridRenderer

set GridRenderer line- and text-style
LineLayer.Renderer: pass relative scale
implement managing of tasks instances in ContinuousTask
rename: ContinuousTask -> SimpleWorker
Tessellator: process all polygons from GeometryBuffer

(not just the first)
use color from Area style in MeshLayer
add option to use MeshLayer for tile polygon rendering
add GeometryUtils.area() for arrays
refactor: TextureItem:

- use different pools for TextLayer and bitmap tiles
  to always get the correct (matching) texture from
  pool.
- the common TextureItem pool is only used to provide
  the same api, it does not keep images or textures
refactor: RenderElement:

- remove curItem
- rename verticesCnt -> numVertices
- add getter/setters
cleanup: Pool
cleanup: Color
what was this sqrt() for?
reduce default of bitmap tiles kept in memory
OBB2D optimizaitons
add GeometryUtils.squareSegmentDistance()
add FastMath.withinSquaredDistance()
add debug draw for MeshLayer