fixed limiter map for vanleer, MC
fixed convert.py for 2d amrclaw and added code and auxiliary files for 2d classic
renamed convert.py to convert46to50.py
added Grady's permute function to permute indices when doing conversion from 4.6 to 5.0
improved and added to tools for converting 4.6 applications to 5.0...
Added Grady's script to permute indices, along with code for classic 2d and 3d conversion.
Open issue: classic code has different calling sequence for qinit, setaux, etc. than AMR versions.
added setrun_template_classic_1d.py
added tools to convert 1d classic codes from 4.6 to 5.0.
changed dt_variable default to True rather than 1 but allow either in setrun.py
fixed 2d typo in Makefile_classic_1d
Merge pull request #57 from rjleveque/conversion

Updates for conversion of 4.x to 5.0 form