Use f90 version of step2
Fixed last function signature
switch to optimized compile flags
Remove extra references to Pi
Minor comment corrections
Updated layered quantities to multilayer module
Adding GeoClaw specific data classes
Start refactor of multilayer module
Merge remote branch 'mandli/rm-layer-density' into rm-layer-density

Conflicts:
	examples/tsunami/chile2010/Makefile
	src/2d/flux2fw.f
	src/2d/rpt2.f