[arch-projects] [archweb] [RFC] Add releng netboot to archweb

[Thomas Bächler]

This is a WIP patch series to add the netboot environment to
archweb. I send it primarily to receive comments on the code
and suggestions for the missing pieces:

- Right now, the binary files needed by pxelinux are not served,
  but are redirects to the old releng site. Only the essential
  files are there, so not everything in the menu will work.
- The files on the information page are not served yet, nor
  do they exist.
- I have no idea if django properly caches this page, or if
  this requires extra configuration, as regenerating it every
  time seems like overkill.
- All files that iPXE needs to access must be served without
  SSL as far as I know.

To test it, set your archweb test environment to run on
 http://localhost:8000/
Download ipxe.lkrn from https://paste.xinu.at/OX7oU8/
and execute
 qemu-system-x86_64 -enable-kvm -kernel bin/ipxe.lkrn
or
 qemu-system-x86_64 -enable-kvm -kernel bin/ipxe.lkrn -cpu kvm32