Signed-off-by: NRémy Coutable <remy@rymai.me>

- Instead of overriding `create` and `update` in `MergeRequests::BaseService`
- Get all merge request service specs passing

Other improvements:
- Ensure slash commands autocomplete doesn't break when noteable_type is not given
- Slash commands: improve autocomplete behavior and /due command
- We don't display slash commands for note edit forms.
- Add tests for reply by email with slash commands
- Be sure to execute slash commands after the note creation in Notes::CreateService
Signed-off-by: NRémy Coutable <remy@rymai.me>

Improve slash command descriptions, support /due tomorrow
Signed-off-by: NRémy Coutable <remy@rymai.me>

Signed-off-by: NRémy Coutable <remy@rymai.me>

Check for update_issuable permission in Notes::SlashCommandsService
Signed-off-by: NRémy Coutable <remy@rymai.me>

Some important things to note:

- commands are removed from noteable.description / note.note
- commands are translated to params so that they are treated as normal
  params in noteable Creation services
- the logic is not in the models but in the Creation services, which is
  the right place for advanced logic that has nothing to do with what
  models should be responsible of!
- UI/JS needs to be updated to handle notes which consist of commands
  only
- the `/merge` command is not handled yet

Other improvements:

- Don't process commands in commit notes and display a flash is note is only commands
- Add autocomplete for slash commands
- Add description and params to slash command DSL methods
- Ensure replying by email with a commands-only note works
- Use :subscription_event instead of calling noteable.subscribe
- Support :todo_event in IssuableBaseService
Signed-off-by: NRémy Coutable <remy@rymai.me>

fixies #19747

Signed-off-by: NRémy Coutable <remy@rymai.me>

Signed-off-by: NRémy Coutable <remy@rymai.me>

This also verify if milestone belongs to correct project before creating
a new issue.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/15439

1. Make the "subscribed" text in Issuable sidebar reflect the labels
   subscription status

2. Current user mut be logged-in to toggle issue/MR/label subscription

1. Allow subscribing (the current user) to a label

- Refactor the `Subscription` coffeescript class
  - The main change is that it accepts a container, and conducts all
    DOM queries within its scope. We need this because the labels
    page has multiple instances of `Subscription` on the same page.

2. Creating an issue or MR with labels notifies users subscribed to those labels

- Label `has_many` subscribers through subscriptions.

3. Adding a label to an issue or MR notifies users subscribed to those labels

- This only applies to subscribers of the label that has just been
  added, not all labels for the issue.

Closes #9014

The only difference with #9014 is that I thoughed the author should also be
able to assign the issue. If this is unwanted behavior Ill revert it.

Everytime the User check or uncheck a Task Item from the Issue or
Merge Request description, a new update is going to be
added to the activity logs of the Issue or Merge Request.

Note that when using the edit form, you can only update the Task item
status or add/delete/modify existing ones. Doing both actions is not
fully supported.

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Closes #2092

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Closes https://github.com/gitlabhq/gitlabhq/issues/7105
See: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/130