Squashed 'Raven.Voron/' changes from 9cd530e..bca5381

bca5381 write batch optimizations

git-subtree-dir: Raven.Voron
git-subtree-split: bca53815f3fafcedb1f5a825094e62069b9ecd01
Merge commit '0ece1995b003726a284cc3a60b56c6854ab7ac94' into 2.5-voron

Conflicts:
	Raven.Voron/Voron.Benchmark/Program.cs
	Raven.Voron/Voron/Impl/TransactionMergingWriter.cs
	Raven.Voron/Voron/Impl/WriteBatch.cs
	Raven.Voron/Voron/Voron.csproj