Format input generator warning text.
Format input generator warning text.

Make it red to indicate that there's a problem, add a heading.

Change-Id: I93d520a88c34d46c48383629c85eaaf607d542fe

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