- Fixed regression introduced in 0.7b4 (!) whereby

- Fixed regression introduced in 0.7b4 (!) whereby
query.options(someoption("nonexistent name")) would
fail to raise an error.  Also added additional
error catching for cases where the option would
try to build off a column-based element, further
fixed up some of the error messages tailored
in [ticket:2069]
- added another huge crapload of tests to the existing
crapload of tests we already had for options..._get_paths()
and dependencies are covered 100% now
- one case still doesn't do the "right" thing, using an option
specific to relationships will silently pass if the endpoint
is a column-based attribute, and vice versa.