Improved lexer error messages
Improved parser error messages
Pass 0-based indexes to CompilerError
Remove redundant filename in error message
Improved compiler error messages
Add some error formatting tests

Thanks to them i discovered that the parser errors where indicating the wrong token ¬¬
Fix failing parser error message test
Optimized `repeat` and its tests
Add CompilationError.fromLocationData
Make error messages show only first line on multi-line errors
Show colorized error messages
Integrate error messages on the REPL
Integrate error messages on the site editor

 Nothing really fancy here; mostly preserves the old format. Maybe if we had a more full-fledged test editor we could show the errors in-line =D

  Also, i couldn't get the `rake doc` task running properly, so i mostly test this editing the index.html directly (ups!).
Remove a couple of TODOs (WONTDOs really)
Make duplicate param name errors mark the actual duplicate parameter

Before:

    coffee> foo = (bar, baz, bar, qux) ->
    repl:1:7: error: multiple parameters named 'bar'
    foo = (bar, baz, bar, qux) ->
          ^^^^^^^^^^^^^^^^^^^^^^^

Now:

    coffee> foo = (bar, baz, bar, qux) ->
    repl:1:18: error: multiple parameters named 'bar'
    foo = (bar, baz, bar, qux) ->
                     ^^^

Also works with destructuring parameters and what have you.
Merge branch 'master' of git://github.com/jashkenas/coffee-script into improved-error-messages

Conflicts:
	Cakefile
	lib/coffee-script/coffee-script.js
	lib/coffee-script/command.js
	lib/coffee-script/nodes.js
	lib/coffee-script/repl.js
	src/coffee-script.coffee
	src/helpers.coffee
	src/nodes.coffee
	src/repl.coffee
Get rid of CompilationError and instead have a couple of functions on helpers.coffee
Remove column number from online editor error box
Rework API for sourcemap filenames and paths.
Remove dead variables.