OK. Here it is. Sorry it took me so long.
First a brief overview:
1> This PPTP/L2TP client patch is for 2.0.1 ONLY!!!! if you choose to apply it to any other version you are likely to break your firewall.
2> I don't know what the effects of running updates on a patched firewall appliance will be. I would suggest DON'T DO IT! At the very least you are likely to have to re-install the patch.
3> pfSense uses the BSD mpd daemon to manage PPP connections (as both server and client). This patch simply exposes a great many more mpd configuration options and generates the required config file.
4> There WILL be bugs. I have not and cannot test all possible combinations. I have however successfully established both PPTP and L2TP connections, between my pfSense appliance at work and my Gentoo Linux server at home and also between two pfSense appliances set up on a test bench.
First ensure you have ssh access to your firewall appliance. Remember your password.
Second, download the patched file from here:https://www.dropbox.com/sh/g3n6muzq0wg7fsg/MP19u-Pbc0
Unzip the package.
Open a terminal and navigate to the newly created directory.
On my Mac and my Gentoo boxes, I use the following command to copy the files to the active firewall appliance:
scp -r ./* root@<IP Address>:/
Windows users can try WinSCP to do this, but I can't help you with that. I presume the command will be very similar.....
Please test and post your results here. I can't promise speedy support, but I'll help where I can. In the meantime I'll continue trying to figure out the correct way to commit these changes to the main trunk.