Converted the instances of const built in types being returned from methods

and passed as paramters into straight forward non const built in types,
i.e. const bool foogbar(const int) becomes bool foobar(int).

src/osg/ClipPlane.cpp

@@ -72,12 +72,12 @@ void ClipPlane::getClipPlane(double* plane) const
     plane[3] = _clipPlane[3];
 }
 
-void ClipPlane::setClipPlaneNum(const unsigned int num)
+void ClipPlane::setClipPlaneNum(unsigned int num)
 {
     _clipPlaneNum = num;
 }
 
-const unsigned int ClipPlane::getClipPlaneNum() const
+unsigned int ClipPlane::getClipPlaneNum() const
 {
     return _clipPlaneNum;
 }