result parser generalized to map arbitrary functions, and some typo
symbolic evaluates and simplifies symbolic results
deprected numerical evaluation, but subexpressions still got bugs
subexpressions are stored in list to avoid resulution errors
__pow__ method uses Expression aritmetics
typo
reordered __pow__ if statement
replace_arguments does not create new Expression on Expression argument
LGPL license added
Update LICENSE

License typo
typo
subexpressions test added
unneccessary imports deleted
rewritten expand method
type and not needed imports deleted
test renamed and __main__.py added
Expression pow test added