Multiple IPStack Related changes (and other bugfixes)

Multiple IPStack Related changes (and other bugfixes)

- Added route determining to arp.c
- Changed route source API to take an interface pointer
- Fixed loopback device behavior ('LOOPBACK' is a special adapter path)
- Required fixing the fifo driver
 > Size on /Defices/fifo directory should be 1, not 0
 > Set default fifo to be blocking
- Slight change to ifconfig to ignore iterfaces that return a -1 type,
  or do not conform to the spec.
- Fixed triple fault when a kernel thread is spawned before init is started
  (caused by a kernel stack being marked as COW, causing an uncatched double
  fault)