Set version to 1.3.0b1

This version number complies with the requirements of StrictVersion, which is
necessary to build an MSI installer.
Add unittest-based test suite

This only contains a couple of trivial tests at the moment, but it is sufficient
to check that the compiled python extension is actually importable.
Fix a compatibility issue with the new Python module
Remove some detritus from SConstruct
Add some more tests of input options
Use the given temperature when checking for suspicous rate constants
Fix calculateReactantMixture to support mechanisms with missing elements

This allows the use of mechanisms that don't hae any species containing carbon
or (less likely) hydrogen.
Add additional debugging information about regridding

Show the grid spacing between added points and the locations, for both
left and right regridding.

Write a 'preAdapt.h5' output file for comparisons with 'postAdapt.h5
Make rate at which boundary grid spacing grows variable

By making this a function of addPointCount, the boundaries are less likely
to extend too rapidly.
Fix docstring typo