[Replicant] [vendor_replicant-scripts] Add a tool and fix small bug in replicant_prepare_patch.py

[Denis 'GNUtoo' Carikli]

In addition to the patches that will follow in a response to
this mail, here's an URL to the see the patches in a web interface:
https://git.replicant.us/contrib/GNUtoo/vendor_replicant-scripts/commit/?id=8241f0706bdd8ea58200aebdcb814869591b16e7

And here's how to get them in a git repository:
git clone https://git.replicant.us/GNUtoo/vendor_replicant-scripts
cd vendor_replicant-scripts
git show 8241f0706bdd8ea58200aebdcb814869591b16e7

Denis.