Add newer way to calculate geometry

Combine the old way to compute the geometry dictionary for subfaults with the
method used in a previous proto-type of the SubFault class.  Adds more
coordinate information and is easier to read.  Also adds a test to compare
the previous implementation with the new.  More work is needed to clean up
where things are expecting the dictionary, currently the new arrays
fault_plane_centers and fault_plane_corners are being unpacked into the
previous variables.
Minor formatting and consistency tweaks
Merge remote-tracking branch 'rjl/dtopotools2' into dtopotools2

Conflicts:
	src/python/geoclaw/dtopotools.py
Change default path for URL data fetching to scratch directory
Move tests from python directory to root
Add tests from python module to tests root
Merge pull request #2 from mandli/dtopotools2

Geometry Modifications