Repair caching / traversals for values

Repair caching / traversals for values

The test suite wasn't running the copy_internals most fixtures,
enable that and try to get all cases working.

Set up selectable.values to do tuple conversion within compilation
step.  at the same time, disable caching for selectable.values
for the moment and make it equivalent to dml_multi_values.

fix cache / compare / copy cases for dml_values and dml_multi_values
which weren't fully tested or covered.

Change-Id: I484ca6e9cb2b66c2e6a321698f2abc0838db1460