(bug 5283) Convert changeemail.bml to TT

Converts changeemail.bml to TT.
(bug 5334) We need version 0.10 of Hash::MultiValue or later
(Bug 5303) Whitelist criticalcommons.org embeds

Adds criticalcommons.org embeds to the whitelist.
Merge pull request #642 from anall/feature/bug5334

(bug 5334) We need version 0.10 of Hash::MultiValue or later
Merge pull request #643 from hotlevel4/bug5303/WhitelistCriticalCommons

(Bug 5303) Whitelist criticalcommons.org embeds
Merge pull request #597 from hotlevel4/bug5283/ChangeEmailRouting

(bug 5283) Convert changeemail.bml to TT
(Bug 5265) Check if $u is defined first

Because logged out users can view the account settings page, which means
$u may be undefined here.
Merge pull request #644 from afuna/fix-notloggedin-settings-bug-5265

(Bug 5265) Check if $u is defined first
(Bug 5265) Print authas menu when we've passed in option to selectonly
Merge pull request #645 from afuna/fix-disappearing-authas-selectonly-bug5265

(Bug 5265) Print authas menu when we've passed in option to selectonly
(Bug 5333) Respect cut text in the inbox on the homepage
Merge pull request #646 from afuna/inbox-frontpage-cut-bug5333

(Bug 5333) Respect cut text in the inbox on the homepage
(Bug 4905) Clean up obsolete code for thread expanding

Used to support talkread.bml only which is now gone; shouldn't affect
any existing code.
Merge pull request #647 from afuna/cleanup-s1-expander-bug4905

(Bug 4905) Clean up obsolete code for thread expanding