change behavior of AttributePatternsParser; attribute must exist for all taxa
change behavior of AttributePatternsParser; attribute must exist for all taxa

adamallo/beast-mcmc,beast-dev/beast-mcmc,beast-dev/beast-mcmc,adamallo/beast-mcmc,adamallo/beast-mcmc,adamallo/beast-mcmc,adamallo/beast-mcmc,beast-dev/beast-mcmc,beast-dev/beast-mcmc,beast-dev/beast-mcmc,beast-dev/beast-mcmc,adamallo/beast-mcmc