Freeze break request for polari

[Florian Müllner <fmuellner gnome org>]

Hey folks,

I'd like to land support for NickServ passwords (https://bugzilla.gnome.org/show_bug.cgi?id=709982) in 3.22. This is a much anticipated feature that required quite a bit of code shuffling (thus the longer review process), though the actual impact on the UI is quite minor:

When we detect that the user writes a (private) "identify" message, we display an InfoBar to offer saving the entered password. If the conversation is currently not visible (for instance when using the /msg command), we also display a notification for the same purpose.

Both cases are strict additions that are displayed in response to user action, not modification of existing elements, so the change has no effect on screenshots/documentation.

There are a couple of string additions though:

 - a description to identify the saved password in gnome-keyring

   ("Polari NickServ password for FreeNode")

 - the infobar title ("Should the password be saved?"), subtitle

  ("Identification will happen automatically the next time you connect to GNOME")

  and button ("_Save Password")

 - the notification title ("Save NickServ password for GNOME?") and body

   (same as infobar subtitle) and button ("Save")

The feature is available on the wip/fmuellner/nickserv branch, which is fairly well-tested by now as all changes during the last month have been minor fixes that came up during review.

Cheers,

Florian