Improve repository hinting and feedback

Summary:
  - Warn about "Read/Write" instead of disabling it, to prevent edits which mutate it after changing a hosted repository to an unhosted one.
  - Warn about authenticated connections with HTTPS auth disabled, and link to the relevant setting.
  - When "Autoclose" is disabled, show that "Autoclose Branches" won't have an effect.
  - For hosted repositories, show the HTTP and SSH clone URIs.
    - Make them easy to copy/paste.
    - Link to credential management.
    - Show if they're read-only.
    - This could be a bit nicer-looking than it is.

Test Plan: Looked at repositories in a bunch of states and made various edits to them.

Reviewers: btrahan, chad

Reviewed By: btrahan

CC: chad, aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7471