Revert "navigator.id.watch when it is appropriate to (bug 825306)"

This reverts commit 066023514efa590a4f110ecff263dbe3af38e79c.
add in a login method
Fix weird form state on validation error (bug 828015)
rename Personas to Themes on AMO (bug 822486)
prompt for the mobile site if we're tiny
workaround for transition z-index issue (bug 822288)
it don't matter whether you're finger or cursor
add in some test coverage (bug 821067)
Fix the tests

Forgot that `_errors` is only updated when there's errors. :(
Fixing tests for @cvan

<3
tweak some positions for Themes subnav (bug 822486)
fix "View Mobile Site" link on legacy AMO pages - i.e., Themes (bug 736249)
404 the user profile page (bug 820424)
Removed walled garden code (bug 812274)