In searchJOIN: substantially rewrote the code for the condition where

In searchJOIN: substantially rewrote the code for the condition where
the JSON query specifies neither of the join columns.

1. Corrected an apparent bug whereby we could join in only one
direction, even when a join in the opposite direction was
valid and equivalent.

2. Rewrote the search loops for better performance.

3. When testing for the success of the searches for join columns,
success should mean that we have identified both columns.  Identifying
just one isn't enough.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@12227 dcc99617-32d9-48b4-a31d-7c20da2025e4