[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
[prep-release-3.1.0-RC1] Update version to 3.1.0-RC1
[prep-release-3.1.0-RC1] Add migration for 3.1.0-RC1
[prep-release-3.1.0-RC1] Prepare Changelog
[prep-release-3.1.0-RC1] Add changelog for 3.1.0-RC1
[prep-release-3.1.0-RC1] Update phpBB Version for RC2 development
Merge branch 'prep-release-3.1.0-RC1' into develop-ascraeus

* prep-release-3.1.0-RC1:
  [prep-release-3.1.0-RC1] Update phpBB Version for RC2 development
  [prep-release-3.1.0-RC1] Add changelog for 3.1.0-RC1
  [prep-release-3.1.0-RC1] Prepare Changelog
  [prep-release-3.1.0-RC1] Add migration for 3.1.0-RC1
  [prep-release-3.1.0-RC1] Update version to 3.1.0-RC1
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [prep-release-3.1.0-RC1] Update phpBB Version for RC2 development
  [prep-release-3.1.0-RC1] Add changelog for 3.1.0-RC1
  [prep-release-3.1.0-RC1] Prepare Changelog
  [prep-release-3.1.0-RC1] Add migration for 3.1.0-RC1
  [prep-release-3.1.0-RC1] Update version to 3.1.0-RC1
[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 branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12766] Event exporter does not like RCx as version