fixed page header
started working on optimistic concurrency
1. fixed an issue when overflow write was performed but split occured
2. added version support for multiadd/delete
multitree - concurrency
added test for missing node
write batch - added version to add and delete
added a comment to unclear code in batch tests that was forcing to build one batch group from incoming batches
Now supporting iterators that can go backward
Minor refactoring
Allow snapshots for multi reads
Slightly better Slice.ToString()
RavenDB-1330 Voron - support deleting trees
Properly account for root page in sub trees
Make sure we write the sub tree record to the right location
RavenDB-1331 Voron - Avoid saving trees that were not modified
Making sure that we can modify tree existence in a transactional manner.
added ReadResult
Merge branch 'voron' of https://github.com/ayende/raven.voron into voron
Minor
Allow to more easily work with read results by putting them in a using statement to dispose their internal Stream