[TransWarp] RFC: DM SPI change

[Phillip J. Eby]

With all this discussion lately about peak.storage and DM's, I'd like to do 
a slight renaming of some DM methods.  It's bothering me that data managers 
are inconsistent with other PEAK abstract base classes, in that the methods 
for overriding in a subclass don't start with '_', even though they are 
private and not intended to be called by users of the DM.  The 'save()', 
'load()', 'ghost()', 'thunk()', etc. methods should all start with '_'.  I 
think this change should be made soon, so that there don't end up being too 
many DMs "in the wild" that will need to change for this.

Any objections?