Replaced the other hash code computation in AlgProp to avoid a round-trip problem.  Overrode the toString in AtomSeq, since it was getting the wrong one from IndexedSeq.  Folded fcmp into the atom comparator to eliminate the method.  Changed how the FastEliParser detects symbols being used as function names.  Added lots of output when round trip testing fails.
Merge pull request #211 from sprowell/master

Small bug fixes for parsing and round-trip.