Cleanup (without any ticket).
Add admin area (REF #4022).
Add admin area (REF #4022).
Merge remote-tracking branch 'origin/master' into 4038-i18n

Conflicts:
	sysinfos-web/src/main/java/ch/alv/sysinfos/ui/config/ApplicationConfig.java
	sysinfos-web/src/main/webapp/i18n/messages.properties
	sysinfos-web/src/main/webapp/i18n/messages_de.properties
	sysinfos-web/src/main/webapp/i18n/messages_fr.properties
	sysinfos-web/src/main/webapp/i18n/messages_it.properties
	sysinfos-web/src/main/webapp/js/application/application-admin.js
Merge with master branch (REF #4038).