Important bugfix in range syntax
fromMb is called fromJust in Data.Maybe
Symmath.Eval now uses Monad Transformers (Reader -> Error -> Identity)
Some more simplify for sums...
Better common factor matching
Fix parser bugs in funName and mathConst
Make parser fail if input isn't consumed completely
Major improvements

Simplify is now able to simplify terms like x - (x - y) to y. Some other
things, too.
Merge branch 'pu/funtable' into next
Merge branch 'pu/parse' into next
Merge branch 'pu/eval' into next

Conflicts:
	Symmath/Eval.hs
Merge branch 'pu/simplify' into next

Conflicts:
	Symmath/Simplify.hs
	Symmath/Util.hs
Doesn't really work this way. Rethink!