kmalloc_align()

Can be freed with kfree().  Same goes for kzmalloc_align().  Alignment
must be a multiple of sizeof long.

Did some basic tests on 32 and 64 bit.  32 bit complains at compile time
(ROUNDUP).  Feel free to fix that, if someone has a nice way.  Or make
the compiler smarter to not complain about casts in branches it'll never
take.
rtl8169 uses aligned kmallocs
Adds some features to 'root' script

It'll still work as before for qemu users: ash root will ifconfig and
mount the same as before (now with a new srv name).

If you want to mount a UFS for one of the other machines that regularly
(but not always) run UFS, ifconfig first, then call for them by name:

$ ash ifconfig c89
$ ash root c75
$ ash root s141

etc.

Feel free to add your own entries to ifconfig and root.