check gcc version and complain clearly if it is too old (i.e., <gcc 4666666)
Merge branch 'master' of https://github.com/UHHAnalysis/SFrameTools
 * extended AnalysisModuleRunner to support the complete AnalysisModule interface now, in particular
   reading additional event input and getting all settings from the xml config without warnings from SFrame
 * invalid identifier now has a name (not an exception); also added "valid" routine to identifier.