prefs: Split lines too long.
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__
prefs: Don't redefine builtin "iter"
prefs: use correct casing for constant.

Also don't reimport GlobalSettings.