Fix: tests: guessed Notification id could be another value if others tests files were previously run in the same session/process.

If you run this test with others in the same process,
like with: "nosetests -xv test_no_host_template.py test_notification_master.py",
then Notification.id may be != 12 ! (why not 42 ? :p)

Just mock Notification.__init__ (the only one we are interested here) and retain the newly created instances in a list.
The one we'll need should be the first (guessed_notif).
"original" stdout can even miss an encoding attribute.

If run "externally" then sys.stdout could be a StringIO for instance,
and have not an encoding attribute.

In such case, defaults to use locale.getpreferredencoding() for printing out unicode strings,
still with xmlcharrefreplace error handler.
missed mock for jenkins requirements.
Enh: make Scheduler a newstyle class.

- To be consistant.
- Used for test debug:
  dynamicaly changed the "action" attribute to a property so
  to trace its usage from the tests.
clean tests: imports of test/shinken_modules.py
Allow to give REGEXPCMD as 6th arg of new_runtest.
to see..