Widget\Tab: no underlined space after icon
Data\Filter: SORT_NATURAL only for PHP >= 5.4
Do not define the constant ICINGAWEB_LIBDIR

This constant should not be needed anywhere.
Level up index.php

This is the preparation for having the Icinga library in PHP's include path.
Fix ICINGAWEB_APPDIR location if the Icinga library is in PHP's include path
Prepare icingacli for having the Icinga library in PHP's include path
Define the ICINGAWEB_VENDORS contant
No longer make ICINGAWEB_APPDIR configureable
Fix include path to the Cli in icingacli
Do not define ICINGAWEB_BASEDIR in index.php

There's SCRIPT_FILENAME. The constants will be removed shortly.
icingacli: Fix "Notice: Constant ICINGAWEB_BASEDIR already defined"
Merge branch 'master' into feature/setup-wizard-7163