permissions: clarify the use of "Permissions" - use "Show Permissions" for the overview 53d6a64ce4f3 wasn't enough. Pages for editing permissions for a subject are always just called "Permissions". Now, pages summarizing the actual permissions to objects are generally named "Show Permissions". This is especially important for User Groups which have both settings and where "Default permissions" just is wrong.

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

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