New reboot system. It shows now a loading gif image without crashing
because of not accessing the WRS anymore.

- Reboot javascript function: displays image, message & reboots without
web crash
- Redirect javascript function: When rebooting, it redirects to index.hp
after 50s.
- All shell_exec("reboot") calls have been replaced by wrs_reboot() in
all files.
- loader.gif added
- new entry to style.css, one for the gif animation and other for the
text.
- reboot.php & rebooter.php carry out the new reboot.

Conflicts:
	userspace/rootfs_override/var/www/endpointcalibration.php
	userspace/rootfs_override/var/www/functions.php
	userspace/rootfs_override/var/www/sfpcalibration.php