minor change in a commented-out debugging print
Treat axes just like variables for indexing purposes.  They're variables in NetCDF,
but not in cdms2 which is why some work is needed here.
Fix minor but in how region is used for buiding id.
1. add method getAxisList() to cdms2.axis.AbstractAxis, so that an axis can be treated more
like a variable
2. minor improvement in reduce_time_space_seasonal_regional() - return right away if there
be nothing to do
3. more special cases for reconcile_units: translate 'mixed' and 'unitless' to 1 (which typically
means fraction but not always) because udunits doesn't understand these terms.  Actually, I don't
really understand 'mixed' but '1' is the only correct translation in the problem I'm looking at.
4. Allow for treating axes similarly to variables at the end of reduced_variable.reduce()
Build in the new file set13.py
1. Generalize stdvar2var a bit by making it a classmethod rather than staticmethod.  E.g. this lets
you use it in conjunction with a standard_variables list other than that belonging to the class
amwg_plot_spec.
2. Give plot set 13 its own standard_variables list, for just CLISCCP.  This is computed in the
new file derivations/set13.py, from FISCCP1.  The bulk of the changes to amwg.py are to make
use of this change.
3. some minor name changes, e.g. varid to varnom
4. Restructure plot set 13's plan_computation, putting some of it into new methods - so the
CLISCCP computation won't make the whole thing too messy.
1. Fix calculation of variable range and assignment of the plot's axes when the variable has
 unusual axes (with no 'axis' attribute).
2. When synchronizing variable ranges (for plot contours), make sure that their units are
consistent.
3. Assign contour levels correctly for boxfill plots.
4. Slightly better warning message when it's not possible to compute data for a plot.
- plot set 13: more robust in type of region input it accepts
- method amwg_plot_spec.stdvar2var: for rvs,dvs return [] rather than None when there aren't any.
This makes more sense but also needs more testing.  It works so far.
- In reconcile_units, a previous commit had set the new mv2.id to the old one.  But
reconcile_units allows mv2 to be a udunits object, which has no id.  I fixed this inconsistency.