BUG: unicode -> utf-8 in Web

[wmoore]

Need to handle strange characters in all web input forms.

See:
​http://www.saltycrane.com/blog/2008/11/python-unicodeencodeerror-ascii-codec-cant-encode-character/

To reproduce, you can copy a chinese character from the link above and paste it into Comment field etc.

Originally reported as #5404 (German input) in web mobile. Fixed with a single commit, since web-mobile doesn't use Django forms here.

[Aleksandra Tarkowska <aleksandrat@…>]

(In [0a409acbf65db68cba2300e2594a560f14ccbf9d/ome.git] on branch develop) this fixes non ascii UnicodeEncodeError? close #5407

[atarkowska]

​http://docs.djangoproject.com/en/dev/howto/deployment/modpython/#if-you-get-a-unicodeencodeerror

[atarkowska]

+ python dist/bin/omero web unittest --config=<http://hudson.openmicroscopy.org.uk/job/OMERO-trunk-components/./component=web,label=linux/729/artifact/src/trunk.config> --test=webadmin
..E...........
======================================================================
ERROR: test_changePassword (omeroweb.webadmin.tests.unittests.WebAdminTest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<http://hudson.openmicroscopy.org.uk/job/OMERO-trunk-components/./component=web,label=linux/ws/src/dist/lib/python/omeroweb/webadmin/tests/unittests.py",> line 690, in test_changePassword
  _changePassword(request, conn, eid)
File "<http://hudson.openmicroscopy.org.uk/job/OMERO-trunk-components/./component=web,label=linux/ws/src/dist/lib/python/omeroweb/webadmin/tests/unittests.py",> line 709, in _changePassword
  if password_form.is_valid():
File "<http://hudson.openmicroscopy.org.uk/job/OMERO-trunk-components/./component=web,label=linux/ws/src/dist/lib/python/django/forms/forms.py",> line 120, in is_valid
  return self.is_bound and not bool(self.errors)
File "<http://hudson.openmicroscopy.org.uk/job/OMERO-trunk-components/./component=web,label=linux/ws/src/dist/lib/python/django/forms/forms.py",> line 111, in _get_errors
  self.full_clean()
File "<http://hudson.openmicroscopy.org.uk/job/OMERO-trunk-components/./component=web,label=linux/ws/src/dist/lib/python/omeroweb/custom_forms.py",> line 12, in full_clean
  for name, field in self.cleaned_data.items():
AttributeError: 'ChangePassword' object has no attribute 'cleaned_data'

[atarkowska]

(In [fd0cd26a43cab0adad3c1e381a14edbd8327bb66/ome.git] on branch develop) this fixes cleaned_data issue #5407