Made vector_to_matrix work for std_vector_c objects that have

non-default allocators.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402225

dlib/matrix/matrix_utilities.h

@@ -1352,13 +1352,14 @@ namespace dlib
 // ----------------------------------------------------------------------------------------
 
     template <
-        typename value_type 
+        typename value_type,
+        typename alloc
         >
-    const matrix_exp<matrix_std_vector_exp<std_vector_c<value_type> > > vector_to_matrix (
-        const std_vector_c<value_type>& vector
+    const matrix_exp<matrix_std_vector_exp<std_vector_c<value_type,alloc> > > vector_to_matrix (
+        const std_vector_c<value_type,alloc>& vector
     )
     {
-        typedef matrix_std_vector_exp<std_vector_c<value_type> > exp;
+        typedef matrix_std_vector_exp<std_vector_c<value_type,alloc> > exp;
         return matrix_exp<exp>(exp(vector));
     }