Adding initial parser implemention, still some rough edges.

* Very basic parser test framework.
* Recognizing rule based parser, using langest match.
    * Backtracking incomplete.
    * State modifying rule system.
    * Copy on divergence, state system for most features.
* Utilities:
    * Comments and white space helpers.
    * Node builder.
* Replicates MDL features sans some bugs and missing specifics.