Fix Python 2.5 support

And fix some PEP8 style issues (mostly about spaces) while I was there.

refs #806

modules/creditmutuel/backend.py

@@ -17,6 +17,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with weboob. If not, see <http://www.gnu.org/licenses/>.
 
+from __future__ import with_statement
 
 from weboob.capabilities.bank import ICapBank, AccountNotFound, Recipient, Account
 from weboob.tools.backend import BaseBackend, BackendConfig
@@ -83,4 +84,3 @@ class CreditMutuelBackend(BaseBackend, ICapBank):
 
         with self.browser:
             return self.browser.transfer(account, to, amount, reason)
-