When running tests from command line, set exit code appropriately.
For scripts, use the Python interpreter that's found on the path.
Include a .cbmfloat pragma to make creating data simpler

Due to the usual vagaries of floating point, these are not completely
perfect, but for "human-scale" numbers it will be OK.
VIC-20 header files
Update manual for 2.1.
Merge pull request #24 from catseye/test-sets-exit-code

When running tests from command line, set exit code appropriately.
Merge pull request #25 from catseye/usr-bin-env-python

For scripts, use the Python interpreter that's found on the path.
Update Windows installer for 2.1
updated platform file descriptions
Document the macros and functions in libbasic64
Fix issue with branches in listfiles.

Due to whitespace vagaries, etc., a sample correct output has been
added to the test case files, but isn't directly checked as part
of verification.