Check if there is an rst_string before converting (and turn it into unicode)

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Add a humanize filter to humanize dates in the templates

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Move the StatusIssue table declaration

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Add a table to store comment on issues

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Add method to the internal API: add_issue_comment to add a comment on a issue

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Add form to add a comment to an issue

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Add endpoint to the application to add comments to an issue

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Improve the issue template

- Display the different comments added to the issue
- Provide more info about who and when that issue was generated

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>