autocomplete: use select2 when selecting users or groups to give permissions This is a minimal change to MembersAutoComplete, inspired by Dominik Ruf. The UX is slightly different than before, with select2 putting up an extra input field, already before typing anything. We use minimumInputLength 1 to get the same behaviour as before and avoid displaying all users in a list.

[tox]
minversion = 1.8
envlist = py{26,27}-pytest

[testenv]
setenv =
    PYTHONHASHSEED = 0
deps =
    -r{toxinidir}/dev_requirements.txt
    py26-pytest: unittest2
    python-ldap
    python-pam
commands =
    pytest: py.test {posargs}