- Fix an inversion in killSecondaryMaster making it kill only primary nodes.
- Add DELAY_SAFETY_MARGIN to make explicit which part of a sleep delay is just here for safety, WRT the "mandatory" part of the delay.
- A disconnected secondary master node must be removed from NM, so its state becomes None.
- Add tests comparing the behaviour of a 2-masters and 3-masters cluster.


git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@1158 71dcc9de-d417-0410-9af5-da40c76e7ee4