smpt mail queue plugin implemented
fix django-settings import
move lettuce.django import into enable() method of plugin
ReasonToFail object has no cause attribute when exception had no message defined

https://github.com/gabrielfalcao/lettuce/issues/384
lettuce smtp mail queue documentation added
Don't Run Feature Hooks If No Feature Scenarios Run

Feature scenarios may not precluded from running because of their
tags or a filter specified using the --scenarios command line argument.
It may be the case that no scenario in a feature runs at all. Previously,
the before and after hooks would still run in that case. This can be
problematic, as the hooks may be used to perform expensive set up or tear
down steps, which would run pointlessly if the scenarios that depend on them
don't run.

Change the behaviour so that before and after feature hooks run only if
scenarios in that feature run.
Merge pull request #397 from rtkrruvinskiy/feature_hooks

Don't Run Feature Hooks If No Feature Scenarios Run
Merge pull request #385 from smartkiwi/master

ReasonToFail object has no cause attribute when exception had no message...
Merge branch 'master' of github.com:mike-grayhat/lettuce into mike-grayhat-master

Conflicts:
	lettuce/__init__.py
	lettuce/django/management/commands/harvest.py