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

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

r18925@haferschleim (orig r2919):  ningu | 2006-11-21 22:44:26 -0800
- slight optimization to ident_condition in PK.pm
- get ident_cond in update() before applying arguments, so a column's pk can be updated
r18926@haferschleim (orig r2920):  ningu | 2006-11-21 22:54:10 -0800
revert update() change
r18953@haferschleim (orig r2922):  ningu | 2006-11-22 12:12:43 -0800
re-commit minimal pk-mutation in update(), with test
r18956@haferschleim (orig r2924):  ningu | 2006-11-22 14:09:07 -0800
add shallow copy of $attrs in ResultSet->new