Implemented the "ref" namespace to get configuration tree references. BUGS: - Tests should be done more thoroughly and extensively - Interaction of tree references and variable substitution should be tested more properly - Documentation is missing yet

# -*- coding: utf-8 -*-

__comment1 = u"Comment 1"
key1 = u"the value"
key2 = 2
key3 = 5.7
key4 = True
key5 = False
key6 = 0o377
__comment2 = u"Comment no 2"
key7 = u"Umlaute: ÄÖÜäöüß"