Where possible moved redundent C header includes from headers to source files

include/osgSim/ShapeAttribute

@@ -14,9 +14,7 @@
 #ifndef OSGSIM_SHAPEATTRIBUTE
 #define OSGSIM_SHAPEATTRIBUTE 1
 
-
 #include <string>
-#include <string.h>
 #include <vector>
 
 #include <osg/Object>
@@ -63,7 +61,7 @@ class OSGSIM_EXPORT ShapeAttribute
        
         void setValue(int value) { free(); _type = INTEGER; _integer = value; }
         void setValue(double value) { free(); _type = DOUBLE; _double = value; }
-        void setValue(const char * value) { free(); _type = STRING; _string = (value ? strdup(value) : 0); }
+        void setValue(const char * value);
 
         /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
         int compare(const osgSim::ShapeAttribute& sa) const;