Moves gocode reference from proposals to supported list in README.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Refactors process class as well as all sub classes.
Process implements virtual methods of all the available
event handlers, so the sub classes don't have to.

Implements the GtkSourceView completion framework and ties it
to the output of the `gocode` daemon. Auto-completion is now
mostly operational. Some tweaks still to be made.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Fixes `gocode` processor and adds configuration options for it
to the config dialog. One can now specify the millisecond delay
after which to display the proposal dialog, as well as whether
or not to run in interactive or user-request mode. The latter
doesn't have any effect at this point and needs to be fixed.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>