Rewrite GTest vector comparisons.
Rewrite GTest vector comparisons.

Some versions of GTest don't permit direct comparison of vectors.

Change-Id: I3040b761d6cbe366f978555661f6d7086628f1d8

OpenChemistry/avogadrolibs,cjh1/mongochemweb-avogadrolibs,ghutchis/avogadrolibs,cjh1/mongochemweb-avogadrolibs,wadejong/avogadrolibs,OpenChemistry/avogadrolibs,wadejong/avogadrolibs,wadejong/avogadrolibs,wadejong/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,cjh1/mongochemweb-avogadrolibs,cjh1/mongochemweb-avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs