DEFINE now remembers input strings of user-defined words.
Organization; whitespace.
Adds missing token-color.
DEFINE can redefine a function wrapped in doublequotes.
COMPILE-AST is simplified.
I've only gotten 'unknown token' when doing extraordinarily foolish things.
define no longer wipes the input.
CLEAR now wipes the input.
...And is thus no longer useless!
DEFINE can now define recursive words.