Integrated shutdown/reboot in AJAX interface including needed sudoers.d ...

Integrated shutdown/reboot in AJAX interface including needed sudoers.d file.
Changed 'index.html' to 'index.php' so that 'config.php' can be included. This allows dynamic name for camera and location.
Added symlink '/var/www/cam.jpg' in installer so that cam.jpg can be used i.e. with iPhone/Android app 'IP Cam View'.