Fixing warnings for taus

One compilation warning in the derivation framework from using an obsolete function (following the documentation suggests simply removing the function call is the right thing)

Three run-time warnings from tau derivation tools for not being set up with a config file. Overridden with an option suggested by the tau developers (thanks David!) to remove the warnings, since this is set up by the tau group in the tau common derivation area and shouldn't throw warnings.

One run-time warning from tau efficiency corrections where a copy-paste seems to have led to two properties that had been given the same name. I hope no one was trying to set one or the other of them (lxr suggests not, at least in committed code).