- started to work on py3k support
- all the changes due to 2to3 script run
- fixed relative import issues
- custom pool worker replaced with python's thread pool executor
- use BytesIO to read http request data instead of StringIO
- added an example to draw custom points on top of openstreetmap background
  map created with modestmaps and matplotlib's basemap
- fixed PIL imports
- removed some of the duplicated imports
- fixed basemap example to use known custom coordinates to be able to
  verify correctnes of points rendering over a background map
- added support for osm cycling layer
- implemented Map.extent property (original Modest Maps Map class provides
  getExtent method)
- fixed matplotlib basemap example to recalculate map bbox
- above recalculation is needed when map of specific image size is
  requested (i.e. when using mapByExtent call)
- removed unused TileQueue.pending method
- removed TileQueue class, which is not needed anymore since Python's
  thread pool executor is used
- TileRequest.load method simplified
  - its caching part is moved to TileRequest.fetch method with lru_cache
    used as default caching mechanism
  - the tile load retry is part of Map.render_tiles method
  - fatbits functionality removed at the moment, to be resurrected in the
    future
- get rid of printlocked function, use logging module instead
- removed unused imports
- removed Map.draw verbose argument as logging module is used to set
  verbosity of messages
- code cleanup
- fetch method used to make http requests moved to module level as
  function, so cached tiles are reused during multiple map redraws
- code cleanup