Allow for private prefixes to method definitions

Fixes #65.
Add default ruby file types Berksfile, Thorfile

Add support for new ruby files types :
- Thorfile : http://whatisthor.com/
- Berksfile : http://berkshelf.com/
Break numerical literal match into discreet parts
Support `0d` integer prefix
Add support for rational and complex literals (2.1)
Add Symbols (Intern) percent string support
Add "i⇥" to insert inspect
Use single quotes on require
Add @ expantion to memoized ivar
Don’t use ||= inside #initialize
Skip multiple extensions in the class name

E.g. an Opal would probably be called my_file.js.rb
inside a Rails application. Previously it generated a class named “MyFile.js”.
Point to ruby 1.8 shim