Bug Fixes - Att, Subst

- Fixed but that required all known attributes to be listed by name
  in order to be recognized by creating new Att::validInternalName
  method.
- Fixed bug in non-global Subst that failed to save a modified
  annotation.

src/tests/subproject.t

@@ -60,7 +60,7 @@ $output = qx{../task rc:sp.rc list project:abc};
 like ($output, qr/\babc\s*$/m, 'abc,ab,a,b | a -> abc');
 
 $output = qx{../task rc:sp.rc list project:abcd};
-like ($output, qr/^No matches.$/, 'abc,ab,a,b | abcd -> nul');
+like ($output, qr/No matches./, 'abc,ab,a,b | abcd -> nul');
 
 # Cleanup.
 unlink 'pending.data';