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.

babel >= 0.9.6, < 2.4
waitress >= 0.8.8, < 1.0
pytest ~= 3.0
pytest-runner
pytest-sugar>=0.7.0
pytest-benchmark
pytest-catchlog
pytest-localserver
mock
sphinx
webtest < 3