Merge 'trunk' into 'DBIx-Class-current'

r12195@localhost (orig r2957):  ash | 2006-12-06 15:48:49 -0600
More descriptive error messages courtesy of Marc Espie
r12196@localhost (orig r2958):  ash | 2006-12-06 17:05:30 -0600
Join condition patch from Bernhard Graf

diff --cc lib/DBIx/Class/Storage/DBI.pm
Simple merge