Squashed 'Raven.Voron/' changes from 6ca0fb4..9cd530e

9cd530e minor
621fc44 Making sure that we are always using the _latest_ pager state visible to the transaction, not the global pager state.
3204483 Skipping long running tests
5f62d84 Fixing tree rebalancing for ref page nodes. Refactoring add node implementation - should be less susceptible for bugs
8b60389 tweaked bug fix - MoveLeafNode() will copy any flag from source node

git-subtree-dir: Raven.Voron
git-subtree-split: 9cd530e34189c8b730a80ed3ca6398a79a33d268
Merge commit 'a0e5a9e0d106f22a644ae27b0440002c4ad096bd' into 2.5-voron

Conflicts:
	Raven.Voron/Voron.Tests/Bugs/PageSplitter.cs
	Raven.Voron/Voron/Impl/AbstractPager.cs
	Raven.Voron/Voron/Impl/MemoryMapPager.cs
	Raven.Voron/Voron/Impl/PureMemoryPager.cs
	Raven.Voron/Voron/Impl/Transaction.cs
	Raven.Voron/Voron/Trees/Page.cs
	Raven.Voron/Voron/Trees/PageSplitter.cs
	Raven.Voron/Voron/Trees/Tree.cs
	Raven.Voron/Voron/Trees/TreeRebalancer.cs