Some changes to win32 package generation
Changed icon set to reflect form of offical ARSnova logo
Add new OSX iconset
Fixed package icon path
Merge branch 'master' of ssh://scm.thm.de/arsnova/arsnovadesktop
Changed LogoWidget to match default ARSnova logo
Some UI changes and prepare for RC1

* Added about/info dialog
* Added actions to menu
* Removed version string from login widget
Changed Sonar configuration and doxygen settings
Change CPack config for RPM and DEB packages

CPack will now check if "dpkg" is installed. If it is available it will
use some configs for DEB packages, if not, it will use configs to build
an RPM package.
Fixed debian architecture detection
Added downloadpage to be updated with CMake
Changed downloadpage template to match new deployment destination
Fixed error in QRCode generation

Server URL setting is used to generate QRCode now
Open links from information window in web browser
Removed obsolete slot
Fixed some memory leaks
Merge branch 'master' into qt5_migration