Changes

I We had a few issues with this one. Versions from 5.84 onwards change installer from NSIS to Windows Installer. This script will uninstall any previous versions which use the old installer and then install the latest version (tested as working with 5.86a). The uninstaller is a little ugly as it uses the appdata in the 'all users' directory, which means that although Iwe'm re using Windows Environment Variables the uninstaller is still english language specific (please do update this page if you find a cleaner or more standard method).