Add an initial Makefile for running jslint
jslint: Add options and global variables
Remove jslint comments (arguments in the make task are used instead)
Remove several helper functions in favor of built-in functions

listfoldl -> reduce method
listfilter -> filter method
listmap -> forEach method
Replace listcontains with a simpler contains function
Remove keyfilter and keyfoldl and use Object.keys, filter, and reduce instead
Merge pull request #2 from BetterBuses/refactor

JavaScript: Remove unnecessary helper functions and add a Makefile for jslint