Big update this time - Core has been redesigned to be multi-user capable. At least...

Big update this time - Core has been redesigned to be multi-user capable. At least partly. (BR #42)
* Architecture changes mostly complete:
  - Core has been split in Core (static) and CoreSession (per-user objects)
  - Connection stuff has been moved out of CoreProxy into Core
  - Lots of cleanups, and we have finally real singletons!
  - Global is now (externally) a static class -- changes throughout the code
* Monolithic Quassel works (or at least it seems to)
* Standalone Core and GUI disabled for now:
  - While most of the new infrastructure is in place in Core, we still need GUI stuff for auth (BR #17)
  - Syncing with Core as well as getting session states not done yet

Next steps will include the redesign of the GUI to make that cleaner as well (BR #41)