Added a basic grunt build system.  Generates two

output files in the `build/` directory, one minifies and the other
basically just concatenates.
Some documentation on the build system.
Added built files.  Some projects don't include their build, but

I think it is the right thing to do in this case.  Following the model
of three.js.
Merge pull request #8 from colinsullivan/build_system

integrating Grunt build system
Added source for documentation from the WAAX.doc repo.
Added doc building to the grunt file.
note on how to build documentation in the readme
Put back beautiful-docs config the way hoch had it before.
Merge pull request #9 from colinsullivan/docs

Documentation merged into build system and main repository.
resolve conflict with newer Polymer (0.2.0)
more fixes on mui
finalizing fixes for new Polymer(0.2.0)
Basic unit testing for Sampler class.

Good enough just to make sure I don't break anything.
Refactored `Sampler` to support `onended` and multiple calls to `stop`.

This implementation is not meant to be a polyphonic sampler, although it
could evolve into one.  I have implemented a list of active nodes instead of
just keeping track of the most recent.  This list is maintained so the nodes
have time to finish and call `onended` before they are removed from the heap.
Since they aren't removed immediately after calling `stop`, it allows `stop`
to be called multiple times, because we wait until the sound actually finishes
to remove the reference to the node.

Calling stop multiple times is specified here:

http://webaudio.github.io/web-audio-api/#widl-AudioBufferSourceNode-stop-void-double-when
updated readme with info on how to run unit tests.
Merge pull request #10 from colinsullivan/sampler_node_management

Sampler node management