Set Application controller default URL options to ensure all url_for calls are consistent
### What does this MR do?
This MR sets the app controller's `default_url_options` so that all `url_for` calls are consistent.
### Are there points in the code the reviewer needs to double check?
Setting these options may simplify `url_for` calls that load the GitLab options already. I did not want to touch existing code yet. I'm also not sure if there are other options that need to be included.
### Why was this MR needed?
If you run GitLab behind a reverse proxy or in a Docker container, you don't want a user to be seeing the local IP and port on which GitLab is running (e.g. 192.168.1.1:8080). Right now there are places where this internal data is leaked (e.g. see the URL in Profile Settings -> Account -> Username; this uses `user_url`).
### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?
#1249
See merge request !453
Fix broken side-by-side diff view on merge request page
### What does this MR do?
This MR fixes the side-by-side diff that was broken in v7.9.0. The "Inline" and "Side-by-Side" buttons are now always rendered with HTML links instead of changing depending on whether the code diff was requested in JSON format.
### Are there points in the code the reviewer needs to double check?
Is there a better way to fix this? The links in JSON format may be desirable if there were a JavaScript hook to handle the buttons, but as far as I can tell there isn't at the moment.
### Why was this MR needed?
The issue is that the code diffs can be generated either by the JavaScript handler or the regular HTML. With the forcing of JSON request format in 27e75344, the JavaScript handler requests the page in JSON format, which it then uses to render the page. However, this has the unintended side effect of requesting that the "Inline" and "Side-by-Side" buttons have references to a JSON-formatted link.
### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?
#1294
See merge request !460
Fix code unfold not working on Compare commits page
### What does this MR do?
The code unfold buttons (`...`) don't work when you go to Commits -> Compare mode. This MR fixes that.
### Are there points in the code the reviewer needs to double check?
Check to make sure all the right initializers are run in the `projects:compare:xxx` case. I'm also not sure if there are other cases where a diff is shown but the code unfolding is not activated.
### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?
Closes#1274
See merge request !434
Milestones and labels can be used even when issues are disabled.
When Issues are disabled for a project Milestones and Labels can still be used for Merge Requests.
See merge request !1739
Fix nested task lists
When nesting task list items, the parent item is wrapped in a `<p>` tag. Update the task list parser to handle these paragraph wrappers.
cc @sytse
See merge request !413
Dmitriy Zaporozhets
Phil Hughes
Keith Pitt
Hannes Rosenögger
Stan Hu
Douwe Maan
Robert Speicher
Valery Sizov
Vinnie Okada
Dmitriy Zaporozhets
Marin Jankovski
Andrew Tomaka
