Add all fields to Convictions model

Add all fields to the Conviction model along with some parsing
methods and validation logic.  In most cases, the validation just
logs an error and happily copies the value.
Update components for spatial mappings of convictions

Update geocoding code.

Factor address cleaning into separate classes.

Add management command for setting county of convictions with home
addresses in Cook County.

Add management command for detecting Chicago Community area based on
geocoded address.

Addresses https://github.com/sc3/cook-convictions/issues/1
Parse sentences into years, months, and days field

Don't autocommit, though this doesn't help database performance
much.

Move database config to local settings.
Add fields and logic to store IUCR offenses based on statutes
Update South version requirements.

South 1.0 doesn't seem to support Python 3.
Add dev requirements for IPython notebook
Add final_statute field and have only one set of IUCR fields

Add a final_statute field to reflect either the ammended statute
if it's present, or the statute if its not.  Base the IUCR code
field on the final statute.  Remove separate IUCR fields for
the ammended statute.
Put analysis IPython notebook under revision control
Add count of records, cases.
s/Conviction/Disposition/

Update model names and calling code to reflect the realization that
records in our data are dispositions, not convictions.

This initially seemed like extra work, but we'll need an actual
Conviction model which we'll extract from the Disposition models.
This will make the queries a lot easier and faster.

Addresses https://github.com/sc3/cook-convictions/issues/41
Update the IPython notebook
Add Conviction model

Add a Conviction model to hold distinct convictions, interpretted
from the disposition records.

Add a management command to create Conviction models from Dispositions.

Add some database indices and QuerySet helper methods to make getting
the earliest dispositions in a case faster.

Addresses https://github.com/sc3/cook-convictions/issues/41
Update IPython notebook

Update our IPython notebook.
Merge pull request #1 from ghing/master

Models and management commands to create Convictions from Dispositions
Add model for census tract

Addresses https://github.com/sc3/cook-convictions/issues/46
Add census data

Add fields to the CensusTract and CommunityArea models to hold
total population and per-capita income from the ACS.

Add a management command to load census data from an American Fact
Finder CSV file.

Add manager and model methods to aggregate census data from tracts
to community areas.

Addresses https://github.com/sc3/cook-convictions/issues/46
add two data crosswalk libraries to reqs
Export Community Area GeoJSON

Add a management command and some custom manager and queryset
methods for exporting Community Area GeoJSON.

Adds a dependency on django-geojson, though we only use their
serializer class.

Addresses https://github.com/sc3/cook-convictions/issues/48
Add additional final fields to Disposition, Conviction

Add the following fields to the Disposition and Conviction models:

* final_chrgdesc
* final_chrgtype
* final_chrgclass

These make Conviction queries easier, especially because statute ids
can be hard to interpret and might not map to IUCR codes.

The fields trickle up from RawDisposition and can be loaded with this
snippet:

from django.db import transaction
from convictions_data.models import Disposition

with transaction.atomic():
    for d in Disposition.objects.select_related('raw_disposition').all():
        d.load_field_from_raw('chrgdesc')
        d.load_field_from_raw('chrgtype')
        d.load_field_from_raw('chrgclass')
        d.load_field_from_raw('ammndchrgdescr')
        d.load_field_from_raw('ammndchrgtype')
        d.load_field_from_raw('ammndchrgclass')
        d.save()
Custom QuerySet and Manager to query by crime category

Add custom QuerySet and Manager classes to query Convictions based
on crime categories.

These categories were suggested by Tracy and are based on a list
of IUCR codes provided by CPD.