Add support for blank fields (Django expects '' not None)

Fixes a bug with postgres, where blank passwords weren't supported.
Add "pgsql" as a PostgreSQL URL scheme.
Bump minor version
Added spatialite backend
Added spatialite to uses_netloc too
Ability to set different engine
Merge pull request #10 from cberner/master

This patch fixes the way urls are parsed to support blank passwords, usernames, hostnames...etc. This is particularly important in dev environments with Postgres, where blank passwords currently don't work
Merge pull request #13 from gabrielgrant/patch-1

Add "pgsql" as a PostgreSQL URL scheme.
Merge pull request #22 from flashingpumpkin/master

Added spatialite backend
Merge pull request #26 from hiisi13/master

Ability to set different engine
Add MySQL (GIS) support

Add mysqlgis url scheme which uses django.contrib.gis.db.backends.mysql,
add a test, and update the README.
Replace Python 3.1 with Python 3.3