update release version and email list.

README

@@ -3,7 +3,7 @@ Please checkout one of the release versions:
 gives you all the available branches. 
 
 The newest release version is obtained with
-   git checkout releases/2.5
+   git checkout releases/2.7
 
 In the subfolder scripts a build script building the dune-fem-howto with all
 necessary dune module dependencies is available.
@@ -11,4 +11,4 @@ necessary dune module dependencies is available.
 This version should also be compatible with the development versions of the
 core. If you encounter problems please report (with all required
 information, e.g., which version on which system you are using) to
-  dune-fem@dune-project.org
+  dune-fem@lists.dune-project.org