Merge 'trunk' into 'sybase'

r5525@hlagh (orig r6682):  timbunce | 2009-06-15 07:30:21 -0700
Added note that column inflation is not performed

r5529@hlagh (orig r6689):  timbunce | 2009-06-16 06:06:07 -0700
Removed wording from txn_do that implies the coderef could be executed more than once.

r5530@hlagh (orig r6690):  timbunce | 2009-06-16 06:14:23 -0700
Added doc note that txn_commit does not perform an actual storage commit unless
there's a DBIx::Class transaction currently in effect

r5531@hlagh (orig r6691):  timbunce | 2009-06-16 06:40:11 -0700
Reverted doc patch r6689 for now, sadly. I'll open a ticket to explain.

r5532@hlagh (orig r6693):  ribasushi | 2009-06-16 08:22:59 -0700
Fix possible regression with prefetch select resolution