Major build system update, repository on a diet

To make upcoming code changes easier, I've put the repository
on a diet (to what it should have been from the start, but
what did I know at the time ... :) ):

- Most git submodules removed (three.js still left, to be
  removed separately)
- Now using bower to manage external dependencies instead of
  replicating the files in this repository
- Lots of old and redundant files removed
Removed hard dependency on three.js git submodule

Created a new manual grunt task which concatenates the few files from
the three.js/examples/js directory which this map needs. The resulting
file is included in the repository and sufficient for regular builds
without pulling in the three.js submodule as well.