Added md_process() to MD layer for generic internal access to hash
process functions

Access to process functions is needed to reduce possible timing attacks
on SSL MAC checks. As SSL is set to move to using the dynamic MD layer,
the MD layer needs access to these process functions as well.
diff --git a/include/polarssl/md2.h b/include/polarssl/md2.h
index 1f60470..02a0a10 100644
--- a/include/polarssl/md2.h
+++ b/include/polarssl/md2.h
@@ -146,6 +146,9 @@
  */
 int md2_self_test( int verbose );
 
+/* Internal use */
+void md2_process( md2_context *ctx );
+
 #ifdef __cplusplus
 }
 #endif