Updates #521 and #536.

Turn the logic around so that a presence stanza is always sent out, except in
the single case where we know for sure that the session was restored, in which
case a presence stanza is not required becaus we "never left".

Should already have been removed in the previous release.

Make sure to send out a presence stanza when one of the following:
1. The connection dropped and the user logged in again
2. Websockets are used (each session is established anew)
3. Keepalive isn't being used in BOSH (each session is established anew).

Also add an introductory section on debugging.

Auto join on invite patch 1 (auto_join_on_invite new parameter)

no-otr compilation issue: Utils is not defined

Updated Hungarian translation

Added the remaining untraslated strings, and also fixed some mistakes in
the translated ones.

Optimized some translations

- The .box-flyout container also needs it's width set upon page load.
- Remove custom height/width upon viewport change (if viewport is small enough).

Compare bare JID of from attr in roster update. @teseo's fix was too specific
and tailored for a misbehaving server (servers shouldn't be sending from the
full JID in a roster push).

- Pending contacts were not aligned to action icons next to them.
- Invite contacts search box went out of bounds on FF

Changed the icon-* selector to apply only to :before (fixes ugly font rendering in FF).

Probably won't make it in next release.

- Round buttons
- Make the head taller
- Wrap name
- Add "view" button for viewing vcard data (needs JS code still).