Revert "C++ bindings: disable generation by default (to follow the efl)."
Revert "C++ bindings: disable generation by default (to follow the efl)."

I'll reintroduce this in a moment, was just easier this way in order to
merge Vincent's changes.

This reverts commit d46fa601ef45d579d1448b19887d02ff2dfbb576.

FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,FlorentRevest/Elementary