Inheritance and filesystem templates.

* Added ability to extend from file system
* Also incorporated compileFromFile method
* Added a template_dir flag to indicate where templates live on
  filesystem.
Removed perlcompileFile function, but instead mock readFileSync and call
perl through this Mock (Thanks to Andrew Rodland for this idea)
Merge pull request #1 from logie17/master

Implementation of compile from file and inheritance via Perl