Hashtable's hash() is now static

Not sure why it was externally visible.
Adds cistrcmp from inferno

Put it in strstr.c, which I think has other inferno stuff.
Changes for netif and devether to compile

Also took care of lock inits and waserror checks.

This ended up being a hacked commit, with the diff of my changes and
Ron's from a806e1fa8d.  Hopefully I didn't screw it up.
Moves netif.c to kern/src/net/