Replace optional dependency to pinocchio to a compilation option (off by default)

CMakeLists.txt

@@ -18,10 +18,11 @@ SET(CXX_DISABLE_WERROR True)
 SETUP_HPP_PROJECT()
 
 ADD_REQUIRED_DEPENDENCY(eigen3)
-ADD_OPTIONAL_DEPENDENCY(pinocchio)
-IF(PINOCCHIO_FOUND)
-  ADD_DEFINITIONS(-DCURVES_WITH_PINOCCHIO_SUPPORT)
-ENDIF(PINOCCHIO_FOUND)
+OPTION(CURVES_WITH_PINOCCHIO_SUPPORT "Build with pinocchio support" OFF)
+IF(CURVES_WITH_PINOCCHIO_SUPPORT)
+  ADD_REQUIRED_DEPENDENCY(pinocchio)
+ENDIF(CURVES_WITH_PINOCCHIO_SUPPORT)
+
 
 SET(BOOST_COMPONENTS unit_test_framework serialization)