Merge 'subqueried_limit_fixes' into 'trunk'

r9296@Thesaurus (orig r9283):  ribasushi | 2010-05-01 11:51:15 +0200
Branch to clean up various limit dialects
r9297@Thesaurus (orig r9284):  rabbit | 2010-05-01 11:55:04 +0200
Preliminary version
r9301@Thesaurus (orig r9288):  rabbit | 2010-05-03 18:31:24 +0200
Fix incorrect comparison
r9302@Thesaurus (orig r9289):  rabbit | 2010-05-03 18:32:36 +0200
Do not add TOP prefixes to queries already containing it
r9303@Thesaurus (orig r9290):  rabbit | 2010-05-03 18:33:15 +0200
Add an as selector to a prefetch subquery to aid the subselecting-limit analyzer
r9304@Thesaurus (orig r9291):  rabbit | 2010-05-03 18:34:49 +0200
Rewrite mssql test to verify both types of limit dialects with and without quoting, rewrite the RNO, Top and RowNum dialects to rely on a factored out column re-aliaser
r9305@Thesaurus (orig r9292):  rabbit | 2010-05-03 21:06:01 +0200
Fix Top tests, make extra col selector order consistent
r9307@Thesaurus (orig r9294):  ribasushi | 2010-05-04 00:50:35 +0200
Fix test warning
r9308@Thesaurus (orig r9295):  ribasushi | 2010-05-04 01:04:32 +0200
Some databases (db2) do not like leading __s - use a different weird identifier for extra selector names
r9313@Thesaurus (orig r9300):  rabbit | 2010-05-05 11:08:33 +0200
Rename test
r9314@Thesaurus (orig r9301):  rabbit | 2010-05-05 11:11:32 +0200
If there was no offset, there is no sense in reordering
r9315@Thesaurus (orig r9302):  rabbit | 2010-05-05 11:12:19 +0200
Split and fix oracle tests
r9317@Thesaurus (orig r9304):  rabbit | 2010-05-05 11:49:33 +0200
Changes