Server/Core: also shutdown on exceptions during fam blocking

Previously the server got stuck, if a keyboard interrupt occured during
block_for_fam_events. The KeyboardInterrupt exception was only handled
in the executable and it does not call shutdown for the Core. So the
running fam thread does not get killed and the main thread waits for it.
Merge pull request #222 from AlexanderS/fix-keyboard-interrupt

Server/Core: also shutdown on exceptions during fam blocking
fix keyboard interrupt during intial event handling

This removes some wildcard except handler because this drops some
KeyboardInterrupt exceptions (for example previously a KeyboardInterrupt
during the loading of the cache for Packages resulted in a fallback to
file read).
Merge pull request #223 from AlexanderS/fix-keyboard-interrupt

fix keyboard interrupt during intial event handling