1. Added a PagerState.Release() statement into the constructor of the PureMemoryPager class.  2. Added tests to ensure that the creation and disposal of pagers leaves the instance count unaffected.
Added lines that break the CanAddVeryLargeValue() test.
Modified the Tree.AllPages() method so that it accounts for overflow pages.
Renamed instances of Overlfow to Overflow.
Removing duplicate set
Tests should not be in an #ifdef