Moved the dataset syncing from the start TH script into the prepare TH script.

There are now actually 2 prepare TH scripts, one that does the sync,
'prepare_node_turbo_hipster_db.sh.erb' and one that doesn't,
'prepare_node_turbo_hipster.sh.erb'. The first is for DB migration tests and
the other is for other jobs run through TH.
Merge pull request #20 from jhesketh/master

Update layout.yaml
Added the missing connection checking to the dataset sync.
Also added some TODO comments.
Update layout.yaml with new regex

New regex to match the new voting patterns on gerrit.
Also remove unused trigger