Aggresive cache convention fix 2.5

Oren,

the commit 'Use the right convention' fixes the commit https://github.com/ayende/ravendb/commit/4b4df3f11a8de9034 where I thing a glitch was introduced because the added convention ShouldSaveChangesForceAggresiveCacheCheck had no usages.

If you confirm it's ok (just by merging it) then I will create a pull request for 3.0