removed PutSerialLock
started working on etag synchronizer
RavenDB-1059 RavenDB does not rollback transaction when an exception occurs during two phase commit

Conflicts:
	Raven.Client.Lightweight/Document/RavenClientEnlistment.cs
fixes in etag synchronizer, and indexers
persistance for etag synchronization
etag synchronization optimizations
Merge branch '2.5' of github.com:ayende/ravendb into 2.5
Rearrange the settings model to the settings folder and namespace
RavenDB-1069 Change Stats tab to fit the Settings and tasks views
Fix the User info view for lists
Fix Logs view to use commands instead of url redirect
Fix views for stats
RavenDB-1056 Cannot delete documents after document count quota is reached
Fix merge issue
performance fixes
added etag synchronization for ReplicationTask and SqlReplicationTask
support for migrated databases
removed expressions
switched to one EtagSynchronizer per client
Started work on RavenDB-968