Plone 4.3 compat + Testing update

Hi all, 

Mostly every issue people report can be solved by pinning correct versions in versions.cfg. So i did a lot of testing and cleanup for Plone 4.0, 4.1, 4.2, and latest 4.3rc1. This pull brings separate buildout file for each of those versions which should work. I added travis integration which tests those Plone versions mentioned above.

Complete changelog:
- Add @kiorky to THANKS.rst
- Don't try to patch ATTopic if ``plone.app.collection`` is available.
- Made all tests pass.
- Add some helper functions to composer which allows ``plone.z3cform``
  to render wysiwyg-widget with TinyMCE on channel edit form which
  passes a composer as context.
- Update buildout(s) and add travis tests for plone 4.0, 4.1, ... 4.3.
- Align package structure to new plone conventions.
- Fix call of ``getSiteManager`` because imports changed from
  ``import zope.component`` to ``from zope import component``.