This commit puts the ground work in place, swapping out the crusty old Logic Editor
UI code for the new RNA-based layout engine. It's disabled with ifdefs at the moment
because it's incomplete, but Dalai can now do the grunt work to fill it all out and get it running.
Also includes a bug fix to LINK buttons, and two new logic operators to add and delete sensors.
Dalai, just switch the #if 0 and #if 1 in logic_window.c:3412 and 3469
