Start some work on more detailed messages of errors
No textwrap.indent in python 2 :(
Add some tests for the new error string representations
Update validate.rst for error printing change
Error strings just show message when there are unset attributes
Fix up the tests for error strings
Add a test for basic error string
Remove some debug print statements
Update errors.rst for error printing change
Fix some other small errors for doctests
Merge remote-tracking branch 'gazpachoking/better_error_messages'
Cleanup.
Change formatting a bit and cleanup the tests.