Fix recently introduced import bugs on master branch.

In an attempt to satisfy the PyDev IDE, I had added "import cython.short" etc.
so that it didn't complain that they were undefined. Unfortunately this
breaks things when you actually run it (with python 2.x).
Fix Exception bug in cantherm/gaussian

It was trying to raise a ChemPyError which does not exits. 
Nothing seems to be done with it so I just replaced it with a generic Exception.
Fix another import.
Fixed unit tests for repr and pickle of kinetics falloff classes.

They were causing an error because they were treating the Arrhenius n values
as double, not ScalarQuantity.
Fixed import statment in translationTest.py.

You can't use a trailing comma in an import statement. (Both the Python
interpreter and the Eclipse UI don't like it.)
Fixed bug in calculateCpInf() for monoatomics.

Monoatomic species must be handled as a special case, as they don't have any
rotational degrees of freedom.
Fixed bug in handling of g/mol and kg/mol when parsing mass quantities.

These must be handled as a special case to get to amu, which is the unit of
mass used internally by RMG-Py. This bug was identified by our unit tests!
Fixed mistake in unit test of Wilhoit.getFreeEnergy() method.

The test had not been updated to reflect the fact that getFreeEnergy() returns
G(T) as a dimensional value (in J/mol), rather than the dimensionlesss G(T)/RT
as once considered.
Moved unit tests of rmgpy.molecule inside subpackage.

By putting the unit test modules next to the modules that they test, it makes
it easier to maintain them. Note that most (but not quite all) of these unit
tests still pass.
Fixed bug in evaluating equivalency of CS atom type.

I forgot to include it in the list of specific cases for R, R!H, and C. Again
this was identified by the unit tests (which I updated to give a somewhat more
informative error message).
Moved unit test for SimpleReactor to rmgpy.solver subpackage.

This unit test still needs some updating, as it is rather out of date.
Updated the SimpleReactor unit test to be functional again.

Besides fixing some imports and some units, I've added a few assertions so
that the unit test actually checks something. I've also commented out the
plotting code so that we can run this test as part of the entire batch
without needing interactivity from the user (to close the plot window).
Moves speciesTest and reactionTest to rmgpy subpackage.

Both of these unit test modules need some updating.
Updated unit tests of Species class to run again.

Oddly, I get a segfault unless I import the rmgpy.species module before any
other rmgpy modules in speciesTest.py. At some point we should figure out why
that is.
Updated unit tests of Reaction class to run again.

All of the unit tests pass.
Fixed bug in Conformer.__repr__() method.

The bug caused the value of E0 to be printed for both the E0 and modes
keyword.
Moved CanTherm unit tests to rmgpy/cantherm subpackage.

These need some updating too.
Restored Gaussian unit tests to working order.

These tests now pass.
Restored geometry unit tests to working order.

Also made a small bugfix in the Geometry class so that the atomic numbers
remain stored in an integer array instead of a float array. (This was
noticed when I tried to repr() a Geometry object, which expects integer
values for the atomic numbers.)
Allow chemkin file to be saved without comments if verbose is turned off.