mkinitramfs-ll.{ba,z}sh: minor keymap update
init: use a fully featured env

Now env can be totaly disabled with case insensitive 0|disable|false|off|no
e.g. env=0, so env=:ikroot:iroot will disable the appendend variables only.
Notice the first required colon, or it wont work properly.
mkinitramfs-ll.conf: use a fully featured env