Always output non-localized dates.

See brutasse/#27

This change makes date fields always output RFC-3339 
format dates as the html5 specification requires.
Removed a bare except following Django's behaviour

See https://code.djangoproject.com/ticket/17888 for context.
Add a layout example with bootstrap
Fixed typo
Merge pull request #50 from Natim/add_bootstrap_layout_as_an_example

Add a layout example with bootstrap
Add a ImageThumbnailFileInput example
Add a snapshot
Update docs/bootstrap.rst

Fix help_text in bootstrap row file.
Merge pull request #57 from novagile/master

Update documentation
use "current stable" version of openlayers for gis widgets

see http://trac.osgeo.org/openlayers/wiki/HowToDownload
Reuse Django's FILE_INPUT_CONTRADICTION

floppyforms did define its own FILE_INPUT_CONTRADICTION constant. Because of
this combining the Django core field with floppyforms widget would fail
(both use different objects for FILE_INPUT_CONTRADICTION). The import
from Django core fixes this problem.
Pull default date/time formats from settings due to localflavor being removed in Django 1.5.
Keep the previous import for backwards compatibility.
As it turns out, default date/time input formats were removed in Django 1.3 and aren't needed at all.
Merge pull request #59 from dmpayton/master

Django 1.5 removes localflavor
Merge pull request #56 from ddanier/issues/56

floppyforms should import FILE_INPUT_CONTRADICTION instead of defining a new object
Merge pull request #58 from i-trofimtschuk/master

use "current stable" version of openlayers for gis widgets
Merge pull request #51 from Natim/add_image_thumbnail_example

Add a ImageThumbnailFileInput example
Switched to the stable/1.5 branch for next django version
Ported the code to run on Python 2 and 3.

This removes Django 1.3 compatibility. Django 1.3 users must stick to an
older version. Also removed some testing code that backported features from
Django 1.4 (assertTemplateUsed, assertHTMLEqual, HTMLParser).

Thanks @aaugustin and @claudep for the porting tips!