Fixes init list bug, makes iterators faster
Fixes init list bug, makes iterators faster

The creation of the combinators happens at the Powersetter level rather
than within the Iterator's constructor.  This fixes the error with the
initializer_lists.

jkhoogland/cppitertools,tempbottle/cppitertools,tempbottle/cppitertools,tempbottle/cppitertools,jkhoogland/cppitertools,ryanhaining/cppitertools,ryanhaining/cppitertools,ryanhaining/cppitertools,jkhoogland/cppitertools