Merge branch 'v2.2' into v2.3

CHANGES/v2.2.txt

@@ -182,9 +182,10 @@ For users:
 For developers:
 - Macports portile is now tested on travis at every plumed push.
 
-Version 2.2.5 (coming soon)
+Version 2.2.5 (Mar 31, 2017)
 -------------
-See branch \branch{v2.2} on git repository.
+
+Notice that branch 2.2 will not be longer maintained! All users are invited to switch to version 2.3.
 
 For users:
 - Fixed a problem with large step numbers in driver (see \issue{209}).