Merge 'trunk' into 'count_distinct'

Merge 'trunk' into 'count_distinct'

r6164@Thesaurus (orig r6163):  ribasushi | 2009-05-07 19:09:01 +0200
 r6115@Thesaurus (orig r6114):  plu | 2009-05-03 10:39:16 +0200
 new branch to fix $rs->update and $rs->delete using the new as_query method

 r6116@Thesaurus (orig r6115):  plu | 2009-05-03 10:52:07 +0200
 Methods update/delete on resultset use now new as_query method to updated/delete properly on joined/prefetched resultset using a subquery. Therefore some tests have been added and some have been changed as well as the warnings around $rs->update/delete have been removed. Cheers!
 r6117@Thesaurus (orig r6116):  plu | 2009-05-03 11:13:48 +0200
 Using "is" instead of "cmp_ok"
 r6160@Thesaurus (orig r6159):  ribasushi | 2009-05-07 11:58:14 +0200
 Back out skip_parens support in as_query
 r6161@Thesaurus (orig r6160):  ribasushi | 2009-05-07 19:00:48 +0200
 This test is completely borked, needs a rewrite
 r6162@Thesaurus (orig r6161):  ribasushi | 2009-05-07 19:07:19 +0200
 Temporary fix or the IN ( ( ... ) ) problem until we get proper SQLA AST (needs SQLA released with commit 6158 to work)

r6165@Thesaurus (orig r6164):  ribasushi | 2009-05-07 19:11:46 +0200
Changes, remove merged branch
r6169@Thesaurus (orig r6168):  ribasushi | 2009-05-07 19:24:54 +0200
Bump SQLA dependency so -in/-between workarounds overload properly