Fixes, mostly for 3D

This contains a bunch of miscellaneous fixes, cleanup work, and a minor feature addition.  Changes:
* use_fwave input parameter now honored in 3D; redundant file flux3fw.f90 removed
* number of time steps in 3D calculated in more robust fashion
* output style now properly declared as integer in claw3ez
* more correct handling of input data and errors in claw3ez
* loops reordered in inlinelimiter.f90 to improve memory access locality
* cleanup of opendatafile.f (2D and 3D)
* change of constant to explicit double precision in inlinelimiter.f90 (2D and 3D) to make gfortran -pedantic happy