In EventMapperTest, suppress notifications created by calling
getExistingTestPage. So far, this test only worked because the existing
test page is created in addCoreDBData (and not inside the test), but
this will no longer be the case after core change
I308617427309815062d54c14f3438cab31b08a73. Clear the PageSaveComplete
hook handlers to prevent that.
DiscussionParser has a static cache of revision data that can become
stale when data is deleted between tests (because revision IDs can be
reassigned to different pages, similar to T344124). This cache seems
needed, and converting the class to a service seems hard, so add the
page title to the cache key to try and avoid collisions. This can still
break if two tests are using the same page, which is hopefully quite
unlikely.
Change-Id: Ic4cbd8ff424e1260544ff9754e0c89dd4bb2f733