Commit: abiwidget stuff

So, the AbiWidget kinda works again. It will even emit GTK+ signals as
you move your cursor/caret around. The problems as I see them are:

*) We need a more reliable way of binding/unbinding the GTK+ signal
listener to/from the Frame's view. Right now, this only works when you
load a file. In a blank document, it'll misbehave.

*) We need to implement more signals. Right now, I implemented a bunch
of character level properties as well as can-undo/can-redo. The output
from a test widget run is below.

*) We emit a lot of signals. We should streamline abi and/or the
widget such that it doesn't emit 20 GTK+ signals every time you type a
character or move left/right.

Boolean signal 'bold': 0
Boolean signal 'italic': 0
Boolean signal 'underline': 0
Double signal 'font-size': 12.000000
String signal 'font-family': Times New Roman
Boolean signal 'can-undo': 0
Boolean signal 'can-redo': 0
DEBUG: Frame Edit mode set to 0
Boolean signal 'bold': 0
Boolean signal 'italic': 0
Boolean signal 'underline': 0
Double signal 'font-size': 16.000000
String signal 'font-family': Times New Roman
Boolean signal 'can-undo': 0
Boolean signal 'can-redo': 0

-- 
Counting bodies like sheep to the rhythm of the war drums.