Use PreBuild Event to execute GUI generate scripts

- Amend existing scripts to not pause at end, clearer output
- New, single script to execute as the prebuild event
- Updated visual studio project file, includes new *UiThreadExec

Signed-off-by: James Warren <admin@trezanik.org>
Remove unused, redundant GUI forms

Signed-off-by: James Warren <admin@trezanik.org>
Update naming convention; EIrcListenerNotification

Replaces E_IRC_LISTENER_NOTIFICATION

Signed-off-by: James Warren <admin@trezanik.org>
Integrate partial but working GUI RPC functionality

Missing most window types and their creation abilities, but testing with
a label works.

Unique ids are a simple incremental counter; will work for a long time,
but not viable for a truly stable implementation. Replace with mapping or
storage as applicable in future.

Signed-off-by: James Warren <admin@trezanik.org>