Integrated various changes worked on at the Glasgow Science Center. Changes

include change the CameraManipulators so they work with double for time
instead of float.  Also added support for DataType to osg::StateAttribute
and StateSet so that they can be set to either STATIC or DYNAMIC, this
allows the optimizer to know whether that an attribute can be optimized
or not.

include/osg/StateAttribute

@@ -149,10 +149,19 @@ class SG_EXPORT StateAttribute : public Object
             COLORMATRIX
         };
 
-        StateAttribute() {}
+        /** Range of types that the StateAttribute can be.*/
+        enum DataType
+        {
+            DYNAMIC,
+            STATIC
+        };
+
+
+
+        StateAttribute():_datatype(STATIC) {}
         
         StateAttribute(const StateAttribute& sa,const CopyOp& copyop=CopyOp::SHALLOW_COPY): 
-            Object(sa,copyop) {}
+            Object(sa,copyop),_datatype(sa._datatype) {}
         
 
         /** Clone the type of an attribute, with Object* return type.
@@ -172,6 +181,11 @@ class SG_EXPORT StateAttribute : public Object
         /** return the Type identifier of the attribute's class type.*/
         virtual const Type getType() const = 0;
 
+        
+        inline void setDataType(DataType type) { _datatype = type; }
+        inline const DataType getDataType() const { return _datatype; }
+
+
         /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
         virtual int compare(const StateAttribute& sa) const = 0;
         
@@ -199,6 +213,8 @@ class SG_EXPORT StateAttribute : public Object
     
         virtual ~StateAttribute() {}
 
+        DataType _datatype;
+
 };
 
 }