fixed Guard check
added failing test for checkpoint counter initlialization
removed checkpoint initialization, increment is an upsert
Merge pull request #263 from seburgi/master

fixed Guard check
Merge pull request #269 from andreabalducci/mongoproviderfix

[Mongo] Checkpoint reset on Initialize
added unique index for CheckpointNumber
Merge pull request #270 from andreabalducci/missingindex

added unique index for CheckpointNumber
Fix wrong generated query for GetCommitsFromCheckpoint.
Merge pull request #275 from mynkow/master

Fix wrong generated query for GetCommitsFromCheckpoint.
Guard fix
Fixes #276 - Pipeline hooks not being invoked when GetUndispatchedCommits
fixed bug in GetFrom(string checkpoint) and added test
Merge pull request #277 from seburgi/get-from-checkpoint

fixed bug in GetFrom(string checkpoint) and added test