Added ASSERTs to PaxosProposer. Removed behaviour from Proposer where PrepareRejected caused flooding.
Added ASSERTs to PaxosProposer. Removed behaviour from Proposer where PrepareRejected caused flooding.

timoc/scaliendb,timoc/scaliendb,scalien/scaliendb,scalien/scaliendb,timoc/scaliendb,scalien/scaliendb,scalien/scaliendb,scalien/scaliendb,timoc/scaliendb,scalien/scaliendb,scalien/scaliendb,timoc/scaliendb,timoc/scaliendb,timoc/scaliendb,scalien/scaliendb,timoc/scaliendb,timoc/scaliendb