doc and changelog

[makedoc]

CHANGES/Unreleased.txt

@@ -22,6 +22,7 @@ Changes from version 2.2 which are relevant for users:
   - Patch script `plumed patch` now patches by default with `--shared`. This should make the procedure more robust (see \issue{186}).
   - Faster \ref GYRATION but new default behavior is not mass weighted
   - Manual is now build with locally compiled plumed
+  - It is not possible anymore to select modules using `modulename.on` and `modulename.off` files. Use `./configure --enable-modules` instead.
 - New actions:
   - \ref FIXEDATOM
   - \ref HBOND_MATRIX

user-doc/Modules.txt

@@ -50,11 +50,8 @@ are available in plumed and tells you whether or not they are active by default.
 
 @MODULES@
 
-Until PLUMED 2.1, the you could only switch on or off modules by adding files
-in the plumed2/src directory:
-- To activate a module add a file called modulename.on to the plumed2/src directory  
-- To deactivate a module add a file called modulename.off to the plumed2/src directory
-Obviously, in the above instructions modulename should be replaced by the name of the
-module that you would like to activate or deactivate.
+Until PLUMED 2.2, it was also possible to switch on or off modules by adding files
+in the plumed2/src directory. Since PLUMED 2.3 this is discouraged, since any choice made
+in this manner will be overwritten next time `./configure` is used.
 
 */