Move 'require' to top of exlib template
pkg_postrm: only remove known files

This whole function is skipped during upgrades, while the Paludis
documentation seems to imply that it should be called.

Investigate.
Switch kernel & initrd compression from XZ to LZO

For teh speedz.

This reverts commit 95a5ceb922271bf3f03710ff1b0fa8b779c594b3.
Update: some drivers added, HMAC version updated
Mangle the pkg_postrm stupidity some more
Don't look up unneeded machine ID