Catch missing spaces mistake in seed mechanisms.
Catch missing spaces mistake in seed mechanisms.

Seed mechanisms are whitespace-delimited, so A+B<=>C+D will not parse correctly.
Until now, the error message did not tell you what was wrong (it was just a 
NullPointerException). This should help catch a common mistake (but perhaps we
should add stuff to the documentation also).
KEHANG/RMG-Java,ReactionMechanismGenerator/RMG-Java,KEHANG/RMG-Java,KEHANG/RMG-Java,jwallen/RMG-Java,rwest/RMG-Java,faribas/RMG-Java,connie/RMG-Java,jwallen/RMG-Java,connie/RMG-Java,connie/RMG-Java,keceli/RMG-Java,connie/RMG-Java,jwallen/RMG-Java,ReactionMechanismGenerator/RMG-Java,nyee/RMG-Java,faribas/RMG-Java,ReactionMechanismGenerator/RMG-Java,nyee/RMG-Java,enochd/RMG-Java,jwallen/RMG-Java,connie/RMG-Java,faribas/RMG-Java,jwallen/RMG-Java,keceli/RMG-Java,keceli/RMG-Java,nyee/RMG-Java,rwest/RMG-Java,enochd/RMG-Java,keceli/RMG-Java,KEHANG/RMG-Java,nyee/RMG-Java,KEHANG/RMG-Java,faribas/RMG-Java,rwest/RMG-Java,KEHANG/RMG-Java,enochd/RMG-Java,keceli/RMG-Java,enochd/RMG-Java,enochd/RMG-Java,ReactionMechanismGenerator/RMG-Java,nyee/RMG-Java,keceli/RMG-Java,ReactionMechanismGenerator/RMG-Java,enochd/RMG-Java,nyee/RMG-Java,rwest/RMG-Java,jwallen/RMG-Java,rwest/RMG-Java