Documented Parser. Changed interface to take single isCmd function instead of a Commands object.
Shell was broken. Fixed include names.
Reverted API of Parser: we now pass the Commands object again instead of just a function. This is in accordance with the approach of having well defined Interfaces and passing them around: passing a function would mean having to bind the one from the Commands instance everytime. We should prefer passing objects.
Added more test cases for Parser.
Fixed visitorExecuter for unterminated JS expressions
Fearlessly deleted most comments and unused code in Line. This is a historical day.