APSTUD-8264 After upgrade to 3.6 switching workspaces requires forcequit

under debugger it looks like AptanaDB/Derby cause this. Derby is overkill for what we're doing here, so I'm going to clean up the code to persist analytics events to disk, and remove Derby altogether.

I hope we wouldn't end up in the synchronization issues that we end up reading the files while there is another thread partially written the analytics event. I guess we even accidentally got into threading timing issues, the missing attributes such as payload and datetime shouldn't really fails while sending the events.