[ticket/12680] Adds alternative text to contact icon in viewtopic.php

PHPBB3-12680
[ticket/12680] Adds second alternativ text and font-size: 0 to remove text

PHPBB3-12680
[ticket/12680] Adds alternativ text with new variable to contact:

PHPBB3-12680
[ticket/12680] Removes unnessesary $user->lang from CONTACT_USER

PHPBB3-12680
[ticket/12680] Little changes, but some issues are still there

PHPBB3-12680
[ticket/12680] Still some problems with displaying the nickname in ucp

PHPBB3-12680
[ticket/12680] Solves last bugs. viewprofile: contact --> contact nickname

PHPBB3-12680
[ticket/12680] Brings back get_username_string()

PHPBB3-12680
[ticket/12680] Adds variable for guest user

PHPBB3-12680
[ticket/12760] Fix wording for unapproved posts icon...

in last post column of forum lists.
https://tracker.phpbb.com/browse/PHPBB3-12760

PHPBB3-12760
[ticket/12766] Event exporter does not like RCx as version

PHPBB3-12766
Merge pull request #2650 from PayBas/ticket/12766

[ticket/12766] Event exporter does not like RCx as version

* PayBas/ticket/12766:
  [ticket/12766] Event exporter does not like RCx as version
Merge pull request #2649 from VSEphpbb/ticket/12760

[ticket/12760] Fix wording for unapproved posts icon...

* VSEphpbb/ticket/12760:
  [ticket/12760] Fix wording for unapproved posts icon...
Merge pull request #2567 from Crizz0/ticket/12680

[Ticket/12680] - Adds alternative text to contact icon in viewtopic.php

* Crizz0/ticket/12680:
  [ticket/12680] Adds variable for guest user
  [ticket/12680] Brings back get_username_string()
  [ticket/12680] Solves last bugs. viewprofile: contact --> contact nickname
  [ticket/12680] Still some problems with displaying the nickname in ucp
  [ticket/12680] Little changes, but some issues are still there
  [ticket/12680] Removes unnessesary $user->lang from CONTACT_USER
  [ticket/12680] Adds alternativ text with new variable to contact:
  [ticket/12680] Adds second alternativ text and font-size: 0 to remove text
  [ticket/12680] Adds alternative text to contact icon in viewtopic.php
[ticket/12462] Do not use string "None" for different options

... it limits translations.

PHPBB3-12462
Merge remote-tracking branch 'nickvergessen/ticket/12462' into develop-ascraeus