Tidy up executables and fix bugs with hashes.

  - Use Trollop gem for option parsing of the rubby excutable.
  - Make rubby binary handle command line options for transpiling,
    target ruby version, optional output file and help output.
  - rubby binary now runs it's first non-option argument by default
    (this makes #! work)
  - irbb now exits on SystemExit (ie when the user types 'exit')
  - Move executables into lib/rubby/commands
  - Fix serialization issues where hases with multiple elements
    contained no commas.
  - Fix parsing issues with hashes where strings where parsed as
    symbols.
  - Bump version to 0.1.3