Add failing test for guid list format.
Make a Save operation to a table with only an Id field always work.

The save operation did not work when the record is already present because the
generated update SQL is invalid, it has no "set" arguments. Admittedly such an
operation is useless, but generating bad SQL is worse, so make the save silently
do nothing except for a debug log entry.
Remove extraneous variable added by mistake and add some update tests.
Merge pull request #363 from BruceCowan-AI/FixNullUpdateToSilentlyDoNothing

Make a Save operation to a table with only an Id field always work.
Merge pull request #362 from tapmantwo/master

Add failing test for guid list format.
Remove exceptions from control flow
fix failing unit test with customizing Guid serialization format