Updated examples.
First attempt at objects.
Merged master -> prototypes.
Correct tests for new expression.
Correct tests for new expression.
Fixed options object in function calls.
Simplified generated javascript for default arguments.
Fixed scope of regular function arguments.
Support for index in for of loops.

For example:
  for element, index in elements
    element.dataset.index = index
  end
Some keywords like delete or when may be used in dot expressions.
Implemented exceptions with begin, rescue and ensure statements.