by initial release:
[X] test regeneration of conf files after filestorage part config change
[X] test .fs files not removed on uninstall
[X] test all error conditions
    [X] incorrect part ordering
    [X] no zope found
    [X] multiple ZEOs found
    [X] invalid zope or zeo parts specified
[X] test inheritance of variables
    [X] devise way to inherit a pattern for naming the filestorages
[X] test manually overriding zope and zeo parts
[X] document all options

nice to have later:
[ ] relstorage support
[ ] blob support
