Merge 'DBIx-Class-current' into 'source-handle'

Merge 'DBIx-Class-current' into 'source-handle'

r34142@cain (orig r2940):  ningu | 2006-11-23 21:39:33 +0000
- nuke old _resultset caching stuff
- teeny cleanup to ResultSetColumn code
r34143@cain (orig r2941):  castaway | 2006-11-23 23:33:42 +0000
Add backup_directory, make tests cleanup

r34148@cain (orig r2946):  matthewt | 2006-11-26 16:21:17 +0000
 r34145@cain (orig r2943):  nigel | 2006-11-26 13:24:39 +0000
 Added a test to check that the result from a 2 level has_many prefetch
 is the same as that got by expanding the relationships one thing at a
 time.