Bug fixes to full model gridding, f2py bug hiding

Step code backwards correctly in B0 space, fix function calls.
Mysterious f2py bug (rminarc=73.71 error) somehow disappeared
after I recompiled (but it didn't seem to have any real reason
before, in my debugging, and may reappear later).  This bug
rules out adaptive rminarc calculation for fear of killing
tabulation + messing up subsequent rminarc calculation.
Debug notes, table generation parameters