Remove deprecate PathAssistedCurrentSiteManager function to fix issue
(using Django 1.5)
  "/private/var/www/django/lib/python2.7/site-packages/multisite/managers.py",
  line 87, in <module>
      class PathAssistedCurrentSiteManager(models.CurrentSiteManager):
Fix following error occurring for who knows why...

Django Version: 1.5.2
Exception Type: NameError
Exception Value:
global name 'constants' is not defined
Exception Location:
/private/var/www/django/lib/python2.7/site-packages/multisite/managers.py
in _validate_field_name, line 50
update version and git repo info
replace django...hashcompat (removed in django 1.6) by python hashlib
Merge remote-tracking branch 'ecometrica/master'

Conflicts:
	multisite/middleware.py
	setup.py
Replace try/except by a test on Django version for
hashcompat/md5_constructor in middleware.py
Replace models.CurrentSiteManager by managers.CurrentSiteManager in
PathAssistedCurrentSiteManager (consider removing it permanently)