Added support for osg::MemoryManager which is based upon Paul Nettle's

memory manager published at flipcode.com.  This can be turned on
with the OSG_USE_MEMORY_MANGER option which then uses custom global
new and delete operators as well as provide osgNew and osgDelete macro's
which add ability to log line and file from which calls are made.

Updated osg,osgUtil,osgDB,osgText and osgPlugins/osg to use osgNew/osgDelete,
and fixed memory leaks highlighted by the new memory manager.

include/osg/Matrix

@@ -40,8 +40,8 @@ class SG_EXPORT Matrix : public Object
             float a20, float a21, float a22, float a23,
             float a30, float a31, float a32, float a33);
 
-        virtual Object* cloneType() const { return new Matrix(); } \
-        virtual Object* clone(const CopyOp&) const { return new Matrix(*this); } \
+        virtual Object* cloneType() const { return osgNew Matrix(); } \
+        virtual Object* clone(const CopyOp&) const { return osgNew Matrix(*this); } \
         virtual bool isSameKindAs(const Object* obj) const { return dynamic_cast<const Matrix*>(obj)!=NULL; } \
         virtual const char* className() const { return "Matrix"; }