On first run this will set your password to encrypt the Nextcloud client configuration (host, user, password) and the data stored in your portable `Documents` folder.
If you ask yourself if 7-Zip is secure enough, please reefer to http://security.stackexchange.com/questions/29375/is-7-zips-aes-encryption-just-as-secure-as-truecrypts-version.
To convert the start.bat to .exe I used Bat To Exe Converter version 2.2.0.0 from http://www.f2ko.de/en/b2e.php.
Currently I need an .exe file because the PortableApps Launcher cannot handle .bat files with the [WaitForEXEN](http://portableapps.com/manuals/PortableApps.comLauncher/ref/launcher.ini/launch.html#waitforexen) setting.