Don't display a leading zero for the first element of the duration.

5 minutes 8 seconds is 5:08, not 05:08
Collapse the buildsummaries on the home page.
Merge pull request #1454 from benallard/patch-1

Collapse the buildsummaries on the home page.
Merge pull request #1452 from benallard/patch-4

Don't display a leading zero for the first element of the duration.
We want the first PrevSuccessfullBuild, not the last one !

This is part of TRAC-3071
Merge pull request #1455 from benallard/patch-1

We want the first PrevSuccessfullBuild, not the last one !
simplify sqlalchemy requirement
Merge sa2ajj/buildbot:sqlalchemy-alchemy (PR #1456)