fix issues #15 #18 #19. change absolute import to relative imports
use different `now` function according to the `USE_TZ` setting
Generic user model to recipient foreign key
Added method to mark as unread too
Added url to mark as unread too

Forgot to pull that when added mark as unread on view
Merge pull request #21 from srtab/patch-1

Generic user model to recipient foreign key
Merge pull request #22 from srtab/patch-2

Added view to mark as unread too
Merge pull request #23 from srtab/patch-3

Added url to mark as unread too
Merge pull request #20 from fay/master

use different `now` function according to the `USE_TZ` setting
Update README.rst
add max version for django-model-utils dependency
Merge pull request #27 from danxshap/model_utils_version

Add max version for django-model-utils dependency
Update README.rst
require django-model-utils >= 2.0.3
Added mark_as_unread in model
Err... Forgot if not
Merge pull request #31 from drager/mark_as_unread

Added mark_as_unread in model
Merge pull request #30 from danxshap/upgrade_model_utils

Require django-model-utils >= 2.0.3
Merge pull request #29 from randomfish/master

Update README.rst
Remove unused import