Allow to send/assign task to project members

### Steps to reproduce
1. Go to a component page
2. Click on 'share'

### Actual behaviour
You get several very public options (twitter, facebook, widgets...)
### Expected behaviour
It would be nice to also have the posibility to share it with a comment with the other translators, it will be even better if you can choose the scope 'translations to language' or 'all' or maybe even usernames
If we provide this option we will make sharing work easier between translators and lower the barrier for cooperation and dialogue.