Added Revive2 to Laidback Potato Challenges and Laidback RNG.

It is my hope this will help bridge the gap between competitive players and casual players. Please be aware and remember that players reserve the right to not revive teammates, particularly if they act in ways that harm teamwork. Work as part of the team or they will leave you behind. You would stay dead the rest of the mission anyway in the other challenges so you lose nothing if they leave you dead. This simply offers the chance to continue to help out your team, if you show you are helpful, useful, and are a team player. Enjoy and have fun - that's what a game is for!

*Author Credits:
- Laidback Potato: Vex
- Laidback RNG: Kyou
- Revive 2: Uzric Rash

I'm also hoping this will fix the issue that the server-side automatic resurrection systems have where you can not resurrect after dying from parasites.

Please let me know about any bugs you find, and I also can take requests to add the Revive2 challenge to any other challenges you'd like, now that I know how it works. Other challenge mergers may be possible too, but mileage may vary.