dev: do not use mknod when creating /dev nodes
pflask: do not check for geteuid() == 0
netif: use sync send so that we get an error back
Revert "dev: do not use mknod when creating /dev nodes"

This reverts commit 7fe580faaffecc08b4dc05ea6295d5b27b313b81.
dev: create /dev/full too
dev: fix /dev/console perms