Remove Piwik autoloader and replace composer autoloader.
Update CustomAlerts submodule and tweak text of travis.sh no group check's error message.
Remove references to old Loader class.
refs #5977 make sure the site selector is always visible
Remove remaining reference to core/Loader.php.
refs #5977 moved the stylesheet definition to forms to make sure it is always applied
Remove TODO from index.php.
Fix bug where certain factory methods assume new operator will throw on class not found (fatal error occurs). Use class_exists to check and then throw exception.
refs #6025 this should show the Events columns again instead of unique visitors
Refactor factory methods into base Factory type for ease of testing.
refs #6026 test for empty in case getenv returns false
Clarify doc for --exclude-path
as suggested in http://forum.piwik.org/read.php?2,118870
use string name of module instead of object itself fixes #6030
refs #5989 #6026 let users define a goal depending on an event and fix the examples and condition was not updated when user changes the match_attribute
Merge pull request #6024 from piwik/composer_autoloader

Switch to composer for autoloading. Add Factory base type for factory types that create classes by string ID and fix bug in those classes where exceptions were not thrown on invalid class name (instead a fatal error ocurred).
Updating composer.lock.
Remove Loader.php reference from cli-script-bootstrap.php.
refs #6028 make sure there is always a value defined as the field is marked as NOT NULL
refs #5124 run automated tests using Mysql sqlmode ONLY_FULL_GROUP_BY
Merge remote-tracking branch 'origin/master'