Add modified organization_item.html snippet

Override CKAN's organization_item.html snippet with a modified one that
works around an apparent bug in CKAN.

The diff from the core template to the modified one is:

33c33
<       <a class="btn btn-small btn-primary" href="{{ url }}">{{ ungettext('{num} Dataset', '{num} Datasets', organization.packages).format(num=organization.packages) }}</a>
---
>       <a class="btn btn-small btn-primary" href="{{ url }}">{{ ungettext('{num} Dataset', '{num} Datasets', organization.packages).format(num=organization.package_count) }}</a>

will submit this as a bug fix to CKAN then this file will be
unnecessary.