Adds J2-X Engine Config for RLA's J-2 (Albatross)

Information obtained from http://www.nasa.gov/pdf/214593main_Bouley%28Lamm%292-26-08.pdf
-max thrust
-min thrust (secondary mode PC)
-Isp

Information obtained from http://www.nasa.gov/pdf/528269main_J-2X_Facts2011.pdf
-confirmation that "secondary mode PC" was the minimum thrust (82% nominal). Look under the capabilities section.

Information obtained from http://www.rocket.com/j-2x-engine
-fuel/oxidizer ratio

This is my first time researching something like this, so please be polite if I screwed something up...