RavenDB-2245 Add additional RavenDB metrics
ported RavenDB-2334 fix from 2.5
restored forcing of Voron storage engine
Multiple tabs works with Studio again

Initial work on shared /changes API connections across tabs. Not
finished, but at least gets us to multiple tabs working again.
RavenDB-2245 Add additional RavenDB metrics
RavenDB-2325 Transformer can return null values
Merge branch 'master' of https://github.com/ayende/ravendb into RavenDB-2325
throw when can't remove dir in test runner
Merge branch 'master' of https://github.com/JudahGabriel/ravendb
Merge branch 'RavenDB_2245' of https://github.com/ml054/ravendb
Merge branch 'RavenDB-2325' of https://github.com/ppekrol/ravendb
GC during server delete
Removing SliceComparer - we will always use NativeMethod.memcmp
Should give us some benefits in not having to do delegate invocation
RavenDB-2344 'etag' property should be removed from metadata during PUT
runner fixed
Do not try to capture stack traces for buffer pool, even in debug mode
Properly handle greater than or equals when the greater than value is on the _next_ page, and there is no equal value.
Merge branch 'runner' of https://github.com/ml054/ravendb
Merge branch 'RavenDB_2344' of https://github.com/ppekrol/ravendb
No need to go over the list of the metadata properties more than once.