qwtpolar, qextserialport, qgis, pikaur and gnucash removal

qwtpolar, qextserialport, qgis and gnucash were removed from and are no longer available on aur-archlinux.

The current alternative is to use the offical versions from the archlinux repo (qwtpolar, qextserialport, qgis, gnucash).

Previous Packages are available in the aur-archive (qwtpolar, qextserialport, qgis, gnucash) for a limited time.