converted MapBase to an NDData stand-in.  Corrected all property attributes so that they are correctly read-only.
has_key is deprecated and removed in 3x (PEP 290)
cleaned up unnecessary calls to dict.get()
updated resample to work with new-style maps
replaced some convenience functions that somehow got dropped.
formatting
translated centre into american
Updated superpixel, rotate, and submap tp use new-style maps
Updates for Yohkoh Maps
Fixed somewhat baffling code branch in is_time to do something useful.
Updated stereo sources to work with new-style Maps
removed references to MapBase
Corrected a property and made output a bit more useful
make date read only
Bring SOHO Maps up to standard for new-style Maps