Removed set_ini function as it will only work if the session path is set to a writable file path - ie PHP is already configured to use file session handling.  If it is using Memcached or some other system, the session path is generally the url for the session storage server and will then break if PHP is forced into file mode.

Also modified documentation on JSessionStorageNone so that it specifies that this session mechanism uses the PHP configured session mechanism, which is generally the file method but does not have to be.
Merge pull request #1839 from garyamort/sessionNoneChanges

Change Session None to use PHP session configuration instead of trying to force file mode