BUG FIX: Allowing netReactions to be irreversible
BUG FIX: Allowing netReactions to be irreversible

In consultation with JWA, MRH believes there are instances where a
netReaction can be irreversible.  For example, model the pyrolysis of
n-propyl radical:

RMG will find 6 pathReactions for n-propyl
   C2H4+CH3
   C3H6+H
   iso-propyl
   CH3+C2H4JJ
   H+C3H6JJ
   H+C3H6JJ

All except the iso-propyl pathReactions are bimolecular Isomers (product
channels) and thus will be "included".  However, the unimolecular Isomer
iso-propyl will not be "included" as this Isomer includes iso-propyl +
all remaining product wells from this Isomer (what MRH understands from
discussion w/JWA).

This commit allows the reading/writing of Restart files to handle
irreversible netReactions.

NOTE: There is a message displayed to screen, anytime an irreversible
netReaction is encountered.  This is meant as a sanity check on our
understanding of the PDepNetwork structure.  This should be removed
before the release.

keceli/RMG-Java,KEHANG/RMG-Java,connie/RMG-Java,rwest/RMG-Java,enochd/RMG-Java,KEHANG/RMG-Java,enochd/RMG-Java,nyee/RMG-Java,KEHANG/RMG-Java,faribas/RMG-Java,connie/RMG-Java,nyee/RMG-Java,KEHANG/RMG-Java,keceli/RMG-Java,nyee/RMG-Java,jwallen/RMG-Java,keceli/RMG-Java,rwest/RMG-Java,connie/RMG-Java,enochd/RMG-Java,ReactionMechanismGenerator/RMG-Java,jwallen/RMG-Java,jwallen/RMG-Java,rwest/RMG-Java,jwallen/RMG-Java,faribas/RMG-Java,nyee/RMG-Java,ReactionMechanismGenerator/RMG-Java,connie/RMG-Java,keceli/RMG-Java,enochd/RMG-Java,KEHANG/RMG-Java,connie/RMG-Java,KEHANG/RMG-Java,faribas/RMG-Java,enochd/RMG-Java,rwest/RMG-Java,jwallen/RMG-Java,enochd/RMG-Java,ReactionMechanismGenerator/RMG-Java,rwest/RMG-Java,nyee/RMG-Java,keceli/RMG-Java,jwallen/RMG-Java,nyee/RMG-Java,ReactionMechanismGenerator/RMG-Java,keceli/RMG-Java,ReactionMechanismGenerator/RMG-Java,faribas/RMG-Java