Bugfix: reverse the order of arguments. Needed because of the shunting yard algo sets them by reverse order.
Fix function name.
Bugfix: fix for literals being tokenized in keywords and variables.
Bugfix: allow strings denoted by : to start with numbers.
Bugfix: handle numbers internally as numbers.
Bugfix: preg_match arguments are in the wrong order.
Also some cleanups.
Cleanups, tweak functions, remove min() and max() since the built-in PHP functions should do the same.