startupwizard: Don't redefine builtin filter
startupwizard: Prefix unused arguments.
startupwizard: Add module docstring
startupwizard: Add docstrings to public and "protected" methods.
startupwizard: Make static methods from methods with no self use.
clipmediaprops: Add comma after space
clipmediaprops: properly UpperCase class name.
clipmediaprops: Add docstrings.
clipmediaprops: Set instance attributes in __init__
clipmediaprops: Switch to new-class style.
depsmanager: Add or break docstrings.
depsmanager: break comments and changes string statement to comments.
filelisterrordialog: Make _addFileExpander a private static method.
filelisterrordialog: add docstrings.
prefs: Switch to new style class
prefs.py: Docstring fixes.
prefs: Run tests if run standalone.

Instead of having to manually set False to True.
prefs: prefix regex string with 'r'
prefs: Set instance attributes in __init__
prefs: Make _fillContents a private method.

Also set attribute "sections" in __init__