Ignore load tests when collective.funkload is unavailable.

Otherwise you get an error, which makes the -D argument to bin/test useless.
Added note about 404 error in test.
Added .gitignore
Fixed "NameError: name 'plone_context_state' is not defined".

This happened when viewing a field with an override.  Other name errors were also
possible.
Issue #29
Thanks to potar for the fix.
Extend test-4.0.x.cfg so we get a bin/test.
Recommend PloneFormGen 1.7+ for Plone 4.1+.
git ignore Products/PloneFormGen/tests/test_form_1_form-folder.tar.gz

This is created by the tests.
Add note about test failure on Plone 4.0 with Retry exception.
Added browser test for the recent fix for viewing a field with an override.

Issue #29