Remove tarball to match the unpacket directory name
make the qemu-kvm name parametric
make the qemu-kvm name parametric even more
Refactor the netmap patches directory
Allow to build KVM with netmap support
Add a pre-patched qemu tarball
Allow to compile a different qemu/KVM tarball
Fix out-of-tree buildcore
Refactor buildcore.sh
Remove useless stuff and fix "host="
Fix the qemu netmap backend
Support using a different host kernel version
Add a config file for a 3.0 host kernel (64 bit only, for now)
Do not unconditionally output information messages

The "RX xxx -> to host blocking" message was printed unconditionally.
Print it only if debugging is really enabled.
Add the missing netmap headers
Fix buildcore.sh
Rewrite the rcS boot script, this time for real!

This simplifies a lot of things, including the autologin mechanism (that
now does not rely on the root's .profile anymore).

Still to be done: check if everything still work (in particular, if
partitions are correctly identified and mounted), and factorise the
partition mount mechanism (after making sure that it does not break).
It can also be simplified a lot...
Do not print an useless warning in rebuildfstab
Add a find_mountpoint() function, from tinycore's rcS
Factorise the "mount partition" code