Updated priorities

- moved lazy querysets to unknown future
- upped custom value stringification issues
- upped invalidate_model() better implementation
A test for weird custom value
Better invalidation for complex and custom fields

Field values are now prepared the same they are in where tree.
Added test for field= and field__exact= non-distinction

Proves #79 is generally a non-issue.
Stringify gis error

Can't stringify <django.contrib.gis.db.models.sql.where.GeoWhereNode object at 0x05FE6830>
Merge pull request #84 from koodjo/patch-1

Fixed can't stringify error for django.contrib.gis requests.
Fixed ImportError when geo libs not present
Auto stringify unknown objects by default
Tox for python 3.4
Do not include NON_SERIALIZABLE_FIELDS into dnf

They were previously included in dnf, but not into object serialization.
These could result into non-invalidable caches hanging.
Updated CHANGELOG
Fix invalidate_model() for proxy models
Updated TODO
Added Python 3.4 classifier
Fixed deepcopy(queryset) bug

Closes #82
Added tests for related and m2m invalidation

Tests require more granular m2m invalidation of both intermediate and
target model.
Fixed working with querysets created by non-patched constructor

Made _cacheprofile and _cloning cached properties, eliminating need to
patch QuerySet constructor.

Should fix dreading #3 and it's duplicates, including #17, #74, #87.
Also circumvents a problem with deepcopying #82.
Updated requirements in README
Add connection degradation support to invalidate_all()

Closes #89
added timedelta to _stringify_query()