Merge 'count_rs' into 'trunk'

r6737@Thesaurus (orig r6736):  ribasushi | 2009-06-20 12:39:34 +0200
new branch to streamline count() and introduce count_rs()
r6738@Thesaurus (orig r6737):  ribasushi | 2009-06-20 12:44:09 +0200
Add count_rs, move the code back from DBI - leave only sql specific hooks
r6739@Thesaurus (orig r6738):  ribasushi | 2009-06-20 12:54:11 +0200
Test count_rs
r6742@Thesaurus (orig r6741):  ribasushi | 2009-06-20 23:30:10 +0200
More tests and a really working count_rs

diff --cc lib/DBIx/Class/ResultSet.pm
Simple merge