Add BOM to files in build output #394

Adds a BOM to all files in the bin directory that have these extensions:
  - css
  - htm
  - html
  - js

Input files have their BOM stripped thru grunt's preserveBOM=false option
(so we won't have BOMs in the middle of concatenated files).

Also removed the base, ui, and css grunt tasks since they are out of date
and unused.