autocomplete: introduce function to set up basic autocomplete functionality To set up an autocomplete instance, there is quite some boilerplate that is with minimal differences between instances. Move this to a helper function to reduce duplication, while still allowing each specific case to tweak behavior.

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

[testenv]
setenv =
    PYTHONHASHSEED = 0
deps =
    nose: nose
    pytest: pytest
commands =
    nose: nosetests {posargs}
    pytest: py.test {posargs}