rename boot.conf to init.conf, change tree by default to init

skel/boot.conf → skel/init.conf

 VERBOSITY=0
 LIVE=/run/66
 PATH=/usr/bin:/usr/sbin:/bin:/sbin:/usr/local/bin
-TREE=boot
+TREE=init
 RCINIT=/etc/66/rc.init
 RCSHUTDOWN=/etc/66/rc.shutdown
 UMASK=0022