Move detect_opencl_devices to scripts directory
Add script to compare PETSc binary dumps as spy plots
spyplot: Only show a single spy plot if one input file given
spydump: use argparse and allow writing the plot to file
Make detect_opencl_devices executable
setup.py: package all scripts in scripts
Merge pull request #179 from OP2/spydump

Add a script spydump to show a spy plot from a binary PETSc matrix dump
or compare two dumps as spy plots if two input file names are given.