FIX: migration name

Was generating: `NameError: uninitialized constant PrivateMessagesHaveNoCategoryId`
FIX: Make extra info header properly responseive

The current solution assumed the width of the logo which caused
the user info and icons bar to shift down when the title is shown.

This fixes that by making the extra info wrapper responsive
and use up the full width, not needing manual breakpoints.
FEATURE: add 'rebake post' in post wrench menu
FIX: clear selection when transitioning out of a topic
FIX: don't always say that an email is not verified in admin
Use a label tag on the checkbox for 'I have read and accept the TOS'
Merge pull request #2783 from chapel/proper-responsive-extra-info

Make extra info header properly responseive
FIX: rake admin:invite sends an email that makes it clear that an account was created for the recipient
lighten staff post bg color
FIX: Scroll position when using the back button
copyedits to welcome PM
FIX: Badges scrolling
whoops duplicate text in welcome PM
Remove unused `titled-link-to` helper
Migrated more helpers to ES6 preferred format
FIX: home icon was incorrectly sized
fixing message highlight in admin
Merge pull request #2785 from awesomerobot/master

fixing message highlight in admin
Use the `{{fa-icon}}` helper on user expansion
FIX: If `latest` is removed (why?) don't 404 on root