Added an advisory note to kinetics libraries documentation.
Added an advisory note to kinetics libraries documentation.

The advice is to add forbidden molecules to a primary thermodynamics library.
Along with the improved error message in 086c9a71d0dc64b9e00a64eeacf5c76053cded49 this closes #249
faribas/RMG-Java,KEHANG/RMG-Java,rwest/RMG-Java,faribas/RMG-Java,enochd/RMG-Java,nyee/RMG-Java,ReactionMechanismGenerator/RMG-Java,rwest/RMG-Java,ReactionMechanismGenerator/RMG-Java,nyee/RMG-Java,connie/RMG-Java,KEHANG/RMG-Java,keceli/RMG-Java,ReactionMechanismGenerator/RMG-Java,enochd/RMG-Java,jwallen/RMG-Java,connie/RMG-Java,keceli/RMG-Java,connie/RMG-Java,nyee/RMG-Java,enochd/RMG-Java,rwest/RMG-Java,connie/RMG-Java,KEHANG/RMG-Java,enochd/RMG-Java,KEHANG/RMG-Java,keceli/RMG-Java,ReactionMechanismGenerator/RMG-Java,keceli/RMG-Java,KEHANG/RMG-Java,rwest/RMG-Java,nyee/RMG-Java,jwallen/RMG-Java,faribas/RMG-Java,enochd/RMG-Java,faribas/RMG-Java,jwallen/RMG-Java,jwallen/RMG-Java,keceli/RMG-Java,jwallen/RMG-Java,rwest/RMG-Java,enochd/RMG-Java,keceli/RMG-Java,connie/RMG-Java,KEHANG/RMG-Java,ReactionMechanismGenerator/RMG-Java,nyee/RMG-Java,jwallen/RMG-Java,nyee/RMG-Java