Merge newest changes with various bug-fixes
Add old dtopotools class structure for reference
Add documenation and fix bugs

Adds and clarifies some of the documentation in the dtopotools module while
also fixing some outstanding bugs from both the dtopotools and topotools
modules revealed during testing.
Raise nose.SkipTest if scipy not installed
Tests all work, new IO test for dtopo added

Also added a few verbose statements to supress output by default.  The IO test
simply reads in test data, writes it out in supported `topo_types`, reads the
same files back in and compares the result with the test data.  Also, a
number of non-usefull temporary path creations were removed.