Added Utils to automatic REPL imports
Added documentation and examples

Squashed commit of the following:

commit a0762b13d969ac71d3cdd747e326e92d9934dc71
Author: Anish Athalye <aathalye@me.com>
Date:   Thu Jul 18 17:14:18 2013 -0400

    Added documentation for Ast and DSL

commit d73331832065f6d37c2c0f1bc67aa2909881e39e
Author: Anish Athalye <aathalye@me.com>
Date:   Thu Jul 18 10:22:16 2013 -0400

    Made Utils a value class

    Making Utils a value class increases efficiency.

commit 56fd7332ea9bab1b5770ecdaed44846a947ce1c4
Author: Anish Athalye <aathalye@me.com>
Date:   Wed Jul 17 14:47:33 2013 -0400

    Updated Ast documentation

commit bc6407b2d6cce251e3df4ea51415c404663a3082
Author: Anish Athalye <aathalye@me.com>
Date:   Wed Jul 17 11:58:26 2013 -0400

    Renamed BaseExtractor.scala to Extractor.scala

commit 01578876d3d0c743b017363209eb277447761ce8
Author: Anish Athalye <aathalye@me.com>
Date:   Wed Jul 17 11:23:28 2013 -0400

    Added documentation to Extractor

commit d4538431340aa5916197a0cd6576d89634ce582c
Author: Anish Athalye <aathalye@me.com>
Date:   Wed Jul 17 11:08:54 2013 -0400

    Added documentation to parsers

commit fa5495cd8f724e746de9292ef709ef9d40e04b49
Author: Anish Athalye <aathalye@me.com>
Date:   Wed Jul 17 10:24:19 2013 -0400

    Added documentation to Utils
Formatted/beautified all source files

Formatted all source files (main and test) using Scalariform.
Updated README