This is the center-most library that all the new static libraries will
be based upon. It provides our core objects, and some new ways to work
with things going forward.

IdeObject is now a bit of a directed graph (without cycles). It provides
a mechanism similar to GtkWidget to destroy hierarchies of objects without
relying on the GObject.dispose directly upon final-unref. Doing so helps
us ensure that we can cleanup objects even if a leak occurs somewhere and
therefore reduce how much we leak.

It also provides us a number of debugging tools going forward to get info
about the object graph.

You can encapsulate a non-IdeObject in an IdeObjectBox which allows
associating it with a tree. IdeBuffer does this so that we can attach
sub-objects to the buffer and have it cleaned up with the buffer. Various
extension points use this for auto-cleanup.

IdeNotification(s) is also used all over in the new design to track
progress of operations. It has convenient UI components in li...