Add rigor to PR Tasks to make them more useful

My group used Code Collaborator with a different SCM before switching over to Git and Bitbucket. In Collaborator, in addition to comments a reviewer can create an "issue" on any line of code, and until the issue is resolved then the review cannot be completed. This is used to ensure that all reviewers' feedback gets addressed and nothing is inadvertently missed.

The Bitbucket "Tasks" are similar to issues in Collaborator but there are some things preventing them from being as useful (in order of priority):

1. Need to enforce that only a reviewer (not the original code author or any subsequent contributors) can close the task. Alternatively, only allow the creator of a task to close it.

• If this is difficult to implement, at a minimum need to send an email notification to the creator of the task when someone closes it so they can verify that their feedback was in fact addressed.

2. Better association of a task/comment with a file. Today when a file is updated the comments/tasks can become disconnected from the file, which is frustrating and adds needless searching or even lost work entirely. In this situation perhaps instead show all disconnected comments aggregated at the top of the file (or even convert them to file comments). A further enhancement would be to allow entering a line number for each one to move it back to the specified line.

3. Allow comments/tasks on any line of code, not just near the changed ones. Not sure why this restriction is in place? It is quite often the case that a code change will have ramifications on code more than 10 lines away from the modified code.

Note that currently we're using Stash 3.11 so my apologies if any of the above has already been addressed in a later version, and if so please let me know and I will bug our IT department to update!