better error message when matplotlib too old
more tweaks for small map areas
more fixes for very small map areas
fix to make meridians and parallels work with very small regions
remove GIST colormaps (I already put them in matplotlib!)
change warning messages in drawparallels and drawmeridians
allow subregions of globe to be plotted for 'ortho' and 'geos'
small cleanups
cleanup mapboundary method.
added 'labelstyle' keyword to drawparallels and drawmeridians.
