FunctionType: Add an optional bool isMethod to ctor, do not check first argument if set.
FunctionType: Add an optional bool isMethod to ctor, do not check first argument if set.

Change-Id: Id42ef7e64da86d6ebb4885c517ebe357bee65cb8

aldebaran/libqi,bsautron/libqi,aldebaran/libqi,vbarbaresi/libqi,aldebaran/libqi