added squashfs support in boot.ipxe

data/apache/files/boot.ipxe

 <?php
 
 $types = [['live', 'unix/live', 'Live'],
+  ['livesquash', 'unix/livesquash', 'Live Squash'],
   ['iso', 'iso', 'ISO'],
   ['install', 'unix/install', 'Installers'],
   ['winpe', 'winpe', 'Windows PE']];
 set options vga=normal ramdisk_size=14332 root=/dev/nfs nfsroot=10.15.44.1:/pxeroot/${live} rw --
 goto boot-unix
 
+:boot-livesquash
+kernel unix/livesquash/${livesquash}/vmlinuz
+initrd unix/livesquash/${livesquash}/initrd.img
+imgargs vmlinuz boot=live config hooks=filesystem username=live noeject fetch=http://netboot/unix/livesquash/${livesquash}/filesystem.squashfs
+boot
+
 :boot-unix
 initrd unix/${unix}/initrd.img
 boot unix/${unix}/vmlinuz ${options}