Let events from all magento areas to fire during unit tests

Previously we only loaded the 'global' event namespace which meant if you defined an event under <adminhtml> for example, it would not be loaded at bootstrap and would not fire during a testcase.

This patch ensures that when setting up a new testcase, all event areas are loaded.

I have also removed the core tests being automatically symlinked by modman/composer. They are broken for all but the most vanilla-install stores and I'm not sure if they even work under 1.8. (Actually...that's another todo :)).