Runs given command as screensaver

Created for https://github.com/sinky/html5-screensaver-node-webkit

• Download AutoIt as ZIP and extract archive (https://www.autoitscript.com/site/autoit/downloads/)
• Run Aut2Exe\Aut2exe_x64.exe an select the runscreensaver.au3 project file
• Click "Convert"
• Rename runscreensaver.exe to runscreensaver.scr
• run runscreensaver.scr /r

/c - configure (asks for the command)
/s or none - run screensaver
/p - used to preview inside screensaver system control panel
/r - register this file as screensaver, without need to copy it to Windows dir