Remove auto plotting of rake
Change to new distance conversion functions
Fix minor bug in colormap specification and add 'asc' file type
added new tests/dtopo1 to test new dtopo and topotools
Merge remote-tracking branch 'rjl/topotools' into topotools
Combine and move new topotools efforts

Moves the new topo and dtopo classes into topotools and dtopotools
modules removing old functions if they have been replaced.  Note that
the dtopotools module is a mess still.  All Okada functionality has been
moved into the dtopotools module.