In oils_cstore.c: fix autojoin, i.e. the facility for constructing

In oils_cstore.c: fix autojoin, i.e. the facility for constructing
a join when the JSON query doesn't specify the columns involved.

When looking up a foreign key linkage in the IDL, ignore the parent
table's end of the link (where reltype = "has_many"), because the
parent doesn't know the name of the column at the other end.

Now an autojoin can work regardless of which table is subordinate
to which.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@12886 dcc99617-32d9-48b4-a31d-7c20da2025e4