Switch from .vash to .html template extension.

* Renamed all templates to have a .html extension instead of .vash
* Set the view engine to handle .html as vash templates
* Removed the hardcoded 1337 port in place of an env.process.PORT variable
  You now need to specify the port explicitly.
Added some more grunt packages for dev workflow

* Added grunt-concurrent to allow concurrent processes
* Added grunt-contrib-watch for live-reload (still a TODO)
* Enter 'grunt defaul' to start running the grunt task