ENH: filters added to mail_admins in logging

http://django.readthedocs.org/en/latest/releases/1.4.html#request-exceptions-are-now-always-logged
ENH: change url template tag to new-style

{% url view_name %} --> {% url 'view_name' %}

https://docs.djangoproject.com/en/1.5/releases/1.5/ (Overview Notes)
ENH: upgrade django-haystack

This commit requires following
1. django-haystack==2.1.0
2. xapian-haystack==2.0.0
3. xapian-python-bindings-for-python-2.7.0==1.2.8
4. Whoosh==2.5.1

This code is NOT backward compatible with older versions of
django-haystack, xapian-haystack
Kindly install xapian-haystack from its repository and NOT with `pip`
https://github.com/notanumber/xapian-haystack/ (master)
ENH: upgrade django-registration

Changes:

1. move built-in registration.backends.default.urls into person.urls (from
scipy_central.urls to scipy_central.person.urls)

2. django-registration latest version NOT compatible with previous
versions. Its majorly written from scratch using class-based `views`
(registration.backends.default.views.RegistrationView)

3. SciPyRegistrationBackend() is inherited from class-based view [2] and
moved into views.py

required packages:
django-registration==1.0