Major refactor:

Implemented GError within the Core Application. Replaced gint returns that only exist to report status with void, implemented GError in functions where they are appropriate. In the spirit of not throwing BoneheadExceptions, added g_assert()s throughout the code to crash on null pointers and such.

Re-implemented the console queue with a GAsyncQueue to resolve some deadlocks I was running into

Deleted existing unit tests. Old unit tests relied on the gint returns. At some point, I will re-implement unit tests using the GLib testing framework.