Python issue #10254
Pywikibot had problems with NFC normalizing unicode,
resulting in Python issue #10254, which was resolved
in Python 2.7.2 and backported to Python 2.6.7.
It is unlikely that supporting Python 2.7.0 and 2.7.1 is still
necessary, so decommission support for Python 2.7.0 and 2.7.1.
Workaround the problem using unicodedata2 backport of unicodedata,
which includes Unicode 7.0 support.
If unicodedata2 isnt available on Python 2.6.6, the Link constructor
raises UnicodeError for titles containing combining characters,
which will allow normal usage for many languages, but will fail
predictably for page titles which could encounter this error.
Moves the unicode test from the version script to the test suite,
as the only supported platform with this bug is Python 2.6.6.