Ignoring failing tests
Minor
Merge branch '2.5-voron' of https://github.com/ppekrol/ravendb into 2.5-voron
Squashed 'Raven.Voron/' changes from d48b105..3bf3e41

3bf3e41 Moving to immutable trees, all trees handling can now be done only through tx. Cloned the values so we won't have aliasing issues.
ac00c72 work in progress --> immutable trees
25b8947 Merge branch 'voron' of https://github.com/ayende/raven.voron into batch_reads
6177623 tweaked bug fix so MoveLeafNode() will copy any flag from source node

git-subtree-dir: Raven.Voron
git-subtree-split: 3bf3e41c73658de89e2c604eb404c8e894e7f408
Merge commit 'e02076b29a1715fa53ca9f10035577554c01a85b' into 2.5-voron
all conflicts resolved "using theirs"
Conflicts:
	Raven.Voron/Voron.Benchmark/Program.cs
	Raven.Voron/Voron.Tests/Backup/CanBackupData.cs
	Raven.Voron/Voron.Tests/Bugs/Deletes.cs
	Raven.Voron/Voron.Tests/Bugs/EmptyTree.cs
	Raven.Voron/Voron.Tests/Bugs/MultiAdds.cs
	Raven.Voron/Voron.Tests/Bugs/PageSplitter.cs
	Raven.Voron/Voron.Tests/Bugs/Snapshots.cs
	Raven.Voron/Voron.Tests/Bugs/TreeRebalancer.cs
	Raven.Voron/Voron.Tests/Bugs/UpdateLastItem.cs
	Raven.Voron/Voron.Tests/MultiValueTree.cs
	Raven.Voron/Voron.Tests/Storage/Batches.cs
	Raven.Voron/Voron.Tests/Storage/Concurrency.cs
	Raven.Voron/Voron.Tests/Storage/MultiTransactions.cs
	Raven.Voron/Voron.Tests/Storage/Restarts.cs
	Raven.Voron/Voron.Tests/Storage/Snapshots.cs
	Raven.Voron/Voron.Tests/Storage/VeryBig.cs
	Raven.Voron/Voron.Tests/StorageTest.cs
	Raven.Voron/Voron.Tests/Trees/Basic.cs
	Raven.Voron/Voron.Tests/Trees/CanIterateBackward.cs
	Raven.Voron/Voron.Tests/Trees/Deletes.cs
	Raven.Voron/Voron.Tests/Trees/FreeSpaceTest.cs
	Raven.Voron/Voron.Tests/Trees/ItemsCount.cs
	Raven.Voron/Voron.Tests/Trees/Iteration.cs
	Raven.Voron/Voron.Tests/Trees/MultipleTrees.cs
	Raven.Voron/Voron.Tests/Trees/Rebalance.cs
	Raven.Voron/Voron.Tests/Trees/Updates.cs
	Raven.Voron/Voron/Debugging/DebugStuff.cs
	Raven.Voron/Voron/Impl/Constants.cs
	Raven.Voron/Voron/Impl/FreeSpaceRepository.cs
	Raven.Voron/Voron/Impl/SnapshotReader.cs
	Raven.Voron/Voron/Impl/Transaction.cs
	Raven.Voron/Voron/Impl/TransactionMergingWriter.cs
	Raven.Voron/Voron/StorageEnvironment.cs
	Raven.Voron/Voron/Trees/PageSplitter.cs
	Raven.Voron/Voron/Trees/Tree.cs
	Raven.Voron/Voron/Trees/TreeDataInTransaction.cs
	Raven.Voron/Voron/Trees/TreeMutableState.cs
	Raven.Voron/Voron/Trees/TreeRebalancer.cs
	Raven.Voron/Voron/Voron.csproj
	Raven.Voron/Voron/packages.config
changes summary
* pulled Voron changes --> now trees are immutable, and belong to transaction only
* as a consequence to Voron changes --> updated all solutions to 4.5 (ImmutableDictionary type)
* minor changes to macro #if statements and removed some references --> reflect update to 4.5