[Doc] Fix Robot kdl documentation issues

src/App/PropertyContainer.cpp

@@ -643,7 +643,7 @@ void PropertyData::visitProperties(OffsetBase offsetBase,
 /** \defgroup PropFrame Property framework
     \ingroup APP
     \brief System to access object properties
-\section Introduction
+\section propframe_intro Introduction
 The property framework introduces the ability to access attributes (member variables) of a class by name without
 knowing the class type. It's like the reflection mechanism of Java or C#.
 This ability is introduced by the App::PropertyContainer class and can be used by all derived classes.

src/Mod/Robot/App/kdl_cp/kdl.hpp

@@ -30,7 +30,7 @@
  * href="http://www.orocos.org">Orocos</a>, but that can be used
  * independently of Orocos. KDL offers different kinds of
  * functionality, grouped in the following  Modules:
- * - \subpage geomprim
+ * - \ref geomprim
  * - \ref KinematicFamily : functionality to build kinematic chains and access their kinematic and dynamic properties, such as e.g. Forward and Inverse kinematics and dynamics.
  * - \ref Motion : functionality to specify motion trajectories of frames and kinematic chains, such as e.g. Trapezoidal Velocity profiles.
  *
@@ -38,7 +38,7 @@
 **/
 /**
  * \page geomprim Geometric Primitives
- * \section Introduction 
+ * \section kdl_geometric_prims Introduction 
  * Geometric primitives are represented by the following classes.
  * - KDL::Vector
  * - KDL::Rotation