Merge branch 'release/0.6.2' into develop
use logger.exception to include a log of the stack trace
Use all indexes that the connection router returns

Connection router returns a list of backends
Add CelerySignalProcessor

The new way for haystack to notify updates are
signal processors. Since they get post_save and
post_delete signals from all models, we have to
filter here with a CELERY_HAYSTACK_MODELS setting.
Add Django 1.5 to travis build matrix
Added some code comments for the settings.
Bumped up the versions.
No crate and no mirrors.
Determine right index without setting

- removes the setting
- checks all backends
- checks if index is instance of CelerySearchIndex
Merge branch 'develop' into signal-processor

Conflicts:
	.travis.yml
Check should_update of index before enqueueing task
Remove obsolete import
Merge branch 'develop' of github.com:jezdez/celery-haystack into develop
Merge pull request #10 from stefanw/signal-processor

Add CelerySignalProcessor
Merge branch 'develop' of github.com:jezdez/celery-haystack into develop

Conflicts:
	celery_haystack/tasks.py
Stop limiting tests to develop branch.
Simplified the index class since 2.X support is now implemented in the signal processor.
Simplified the signal processor to be closer to the queued_search implementation.
More relative imports.
Raise an exception if using Haystack 2.X and not having defined a HAYSTACK_SIGNAL_PROCESSOR setting.