Some minor improvements to itdata.h, mostly names of variables.
Fixed Makefiles to include boost headers, required by btas/range.h
Added overloads of detail::call for functions and function objects with no return value (i.e. returning void).
Major redesign of ITData visitor objects and applyFunc methods. Now applyFunc can be called as applyFunc<FuncObjType>(p_itdata,{fobjargs,…}); and applyFunc returns a copy of the function object created internally for cases where the object holds a value which needs to be extracted. Most importantly, the new design only requires registering all ITData subtypes only once for each type of function object (ConstFunc1,Func1,Func2,Func2Mod) instead of having to register all possible pairings of ITData subtypes. Otherwise there would be a combinatorial explosion of functions that would need to be declared.