temp commit
Can now check if we need to flush
Starting RavenDB-1449
Merge branch 'voron' of github.com:ayende/raven.voron into voron

Conflicts:
	Voron.Tests/Trees/Updates.cs
	Voron/Impl/Journal/WriteAheadJournal.cs
Merge branch 'RavenDB-1449' of github.com:ayende/raven.voron into voron

Conflicts:
	Voron/Impl/Journal/WriteAheadJournal.cs
Minor
Do not expose this in this fashion, might have concurrency implications
Merge branch 'voron' of github.com:ayende/raven.voron into voron
* Avoid allocating the buffer on every file copy
* Make sure that we take the log files _while in a write transaction_, to avoid modifications while we are reading from them.
Fixing the build
RavenDB-1449 Ensure coherent strategy exists for concurrent log flush in Voron
RavenDB-1452 Voron: sync data file after updating headers
We actually need a robust way to delete a directory, dear Lord