[REM] reverted the populate functionality, moving to extra addon

[REM] reverted the populate functionality, moving to extra addon
[REF] split up LDAP authentication in atomic methods
[REF] remove unnecessary lambdas from defaults
[REF] improve pep8 compatibility
[REF] remove unnecessary conditionals when an exception is raised anyway
[IMP] do not log redundant exception ldap.INVALID_CREDENTIALS
[IMP] replaced generic exceptions by ldap subclass
[FIX] update timestamp when LDAP user logs in
[FIX] prevent inactive LDAP users from logging in
[FIX] select first menu item for new users by id, not by name
[FIX] use ldap.search_st() which actually does take the timeout argument

lp bug: https://launchpad.net/bugs/784501 fixed

bzr revid: stefan@therp.nl-20110622102118-syfszkpb0mwme4q5