Alexis S. L. Carvalho <alexis@cecm.usp.br> [Fri, 14 Mar 2008 09:56:58 -0300] rev 6257
dirstate: ignore mode changes if the fs does not supports the exec bit
This can make a difference when e.g. the repo is exported through NFS
(which support exec bits) and CIFS (which does not).