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

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

r13301@evoc8 (orig r2696):  dyfrgi | 2006-08-21 10:33:04 -0500
Change _cond_for_update_delete to handle more complicated queries through recursing on internal hashes.
Add a test which should succeed and fails without this change.
r13302@evoc8 (orig r2697):  blblack | 2006-08-21 12:33:02 -0500
bugfix to Oracle columns_info_for
r13321@evoc8 (orig r2716):  dwc | 2006-08-22 00:05:58 -0500
use ref instead of eval to check limit syntax (to avoid issues with Devel::StackTrace)