pcb - How to design a new board comprised of multiple already designed sub-boards separated by breakable tabs?

I want to take advantage of the entire 5cmx5cm given to me by places like DirtyPCBs and Elecrow so i want to design multiple separate PCBs on kicad and then combine them onto one board (like shown in the "panelizing" section of this FAQ page) with this type of breakable tab (slots or mouse bites) as shown in this image from DirtyPCBs. I just started to learn how to design boards with kicad and so far all i have designed is a 777 timer LED blinker and a bluetooh module breakout. I ordered these designs already from OSHPark for one and Elecrow for the other but I want to try and combine the completely separate PCBs onto a single one and add the breakable slots.

Is there an easy way to do this with KiCAD? Or on another program? Can i design all the circuits schematics separately and make all their board layouts separate and then import the board layouts into another board layout project to combine and add the slots?

Note that these aren't V-Grooves. These are just parts of the PCB that are meant to be broken away.

EDIT: by "or another program" i mean a third party program that takes the output of kicad pcb modules or even just gerbers and does it. That way i dont have to rework my entire design flow

Answer

You can do this in Kicad if you start pcbnew directly. There is a nice tutorial on panelizing with KiCad.