1.x backport: Allows patch-level to be specified per-project.

[jhedstrom]

• Backport to 1.x
• Reroll of Allow forcing the patch level (-pX) for a particular package #101
• Fixes Patch for new file applied to incorrect location #43

[bkosborne]

Would love to see this in! We're also having issues with applying Drupal core patches that introduce new files. They go to the wrong place.

[MPParsley]

Indeed, this should go in 1.x

[fenstrat]

This works a treat for core patches. Would also love to see this in 1.x.

[cweagans]

Despite what I said before, I'm okay with this. It's pretty low risk and solves some immediate problems for people using composer-patches. While I would really like to say that this is a 2.x feature, the reality is that 2.x isn't moving along as quickly as I'd like, and it's not fair to make people wait for something that doesn't have a realistic release date set.

Thanks for bringing this back up, and sorry I didn't give it more consideration before.