Add autofs and install cefs configuration

[mattgodbolt]

Extracted part of #798

Large formatting changes are only me adding autofs and sorted the lines (even though the python versions seem ... odd I haven't touched that).

cefs changes tested and only affect paths pointing at /cefs which will automount stuff in /efs/cefs-images

[mattgodbolt]

didn't seem to have taken effect, so will investigate later

[mattgodbolt]

Of course I have to commit before I can build doh

So will do so. Also have a slightly different (but backwards compatible) approach to cefs automount brewing. But this is a decent start.