Adds a make_m2m flag to Mommy class to handle if ManyToManyFields will or will not be created
Update the docs
Sorry, I was yelling too much on this title...
Use try/except with import error to remove PIL dependecy
Removes PIL from install requirements
Remove PIL from travis.cfg
Implement helper to use datetime with timezones as required by Django 1.4+.
Refactor `datetime.now` to the new helper `timezone.now`.
Implement `smart_datetime` to align with different Django versions
Refactor `datetime` to `smart_datetime`
Refactor TestRunner import to `get_runner` helper

This helper is available since Django 1.1.
Eliminate the need for a test_settings.py file.

Currently the code rely on `DJANGO_SETTINGS_MODULE` to setup Django settings to run the tests.
Implementing the function `configure_settings` we make `runtests.py` self contained.
However, it still is possible to override the programmed settings:

```bash
DJANGO_SETTINGS_MODULE='path.to.some_settings' ./runtests.py
```
Prepare to add more complex command arguments.
Add --use-tz flag to test model_mommy with timezone aware datetime.
Add tox to the project
Configure tox environments

* django1.4 (*USE_TZ=False*)
* django1.4-timezone (*USE_TZ=True*)
Update README testing instructions
Force string gen to only use letters avoiding non-printable chars
Merge branch 'feature/m2m-optional-creation'

Conflicts:
	README.md
Merge pull request #60 from berinhard/topic/remove-pil-dependency

Remove PIL dependecies