Add form used to add inline comments in a pull-request
Remove the paragraph around the description, rst2html already takes care of it
Update the format_loc filter

With the new format_loc filter if a commit is provided at the same time
as the line of code, the filter will add an extra column (hidden by
default) containing the image that the user should click on to add a
comment on that line of code.
This new filter will also add some meta information used by our tool to
find out which row of which commit the comment should be added to.
Specify the CSS for the new cell added by the format_loc filter
Update the pull_request template to use the new format_loc filter
Add a pull_request_comment template

This template is used embedded in the pull_request template when the user
asks to add a comment in a pull-request
Therefore, this template does not inherit from any other template
Add a new pull_request_add_comment endpoint

This endpoint is the one called/used when adding an inline comment to a
pull-request
Add javascript logic to show/hide the comment panel allowing inline comments in pull-requests