Fix an indentation problem (probably from a merge) which left contour and vector plots only
partially set up.
This code would be better organized if the common min/max code were in a separate function, rather
than doing it with all these if/elifs.
Also I tweaked the calculation of the stride between plotted vectors.  It probably doesn't belong
here at all, but it's the best place available at the moment.  I'm not sure that the stride is
universally good, but at least the code is more transparent than before.
Add metadiags.py script.
Also:
Some fairly minor usability changes -- realms now have a coords and filekey. added --xml option (primarily used in diags.py). added --outputpre/--outputpost options for tweaking filenames
icky hacks for questionable units in obs sets
Add TGCLDLWP->TGCLDLWP_OCEAN to the special vars; also stop printing varlist from amwg set 4
check for available sets vs user requested sets
oops typo
fix usage instructions
Add 'possibly bad data' to cdscan failure print
add /climos to the output directory
add database-update only option
add some command line arguments to be consistent with diags.py
add '%' as well as 'percent' when we are converting from fractions to an understood udunits nvalue
add the cdscan command when cdscan fails
Add check for which sets are actually available
add support for table generation
remove : from what eventually becomes the filename. Makes SCP complicated. Probably should have a more trivial way to generate the filename without having to know which season/region is involved and without trying to extract those from the title
add topten to list of valid set names