Clarified spec

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403940

dlib/smart_pointers/scoped_ptr_abstract.h

@@ -37,6 +37,7 @@ namespace dlib
             REQUIREMENTS ON deleter
                 Must be a function object that performs deallocation of a pointer
                 of type T.  For example, see the default_deleter type defined above.
+                It must also not throw when constructed or when performing a delete.
 
             INITIAL VALUE
                 defined by constructor