fix test for plone>4.3.11

[frisi]

from plone4.3.12 onwards, tests related to PrettySubscriptionsForm are broken.
(see #32 for some more details on that)

when removing the version pins done by http://dist.plone.org/release/4.3.17/versions.cfg in version.cfg additional tests are broken

[versions]
# pinned in plone's versions.cfg
#z3c.form = 3.2.11
#zope.testbrowser = 3.11.1
#collective.z3cform.datetimewidget = 1.2.8
#five.intid = 1.0.3
#z3c.batching = 1.1.0
#z3c.formwidget.query = 0.16

# update to most recent and compatible versions
mechanize = 0.2.5
BeautifulSoup = 3.2.1
cssutils = 1.0.2
StoneageHTML = 0.2.1
zc.lockfile = 1.3.0
zc.queue = 1.3

need to:

• remove pin to 4.3.11 in test-plone-4.x.cfg
• fix tests (search for differences in z3c.form related packages shipped with 4.3.11 and 4.3.12)