In this directory is a hacked-up instance of nos-tun.  Significant changes
include:

  o  -r and -w flags.  The main reason in adding these is for the case when
     you might have a tunnel going across a link with a dynamically
     assigned IP address.  Should a write fail (ie, after a link went down)
     nos-tun will attempt to bring down the tunnel and bring it up again
     to restore the connection.  Using hostnames for destination addresses
     was already supported, so this may work well with networks using 
     dynamic DNS (eg, dhs.org)

  o  Return code from write(2) and send(2) is used now.  Incomplete
     writes are now handled properly.  Failed writes may be handled
     with -r (above)

  o  Moved some code around so that subroutines aren't calling exit(3). 

  o  Capitalized "Cisco" in the manpage, and changed the use of the word
     from a generic product to an adjective modifying the word "router"
     in order to protect Cisco's trademark.

Feedback I'm looking for: does this work as expected?  Does the write
failure recovery seem to work ok?

I am only responsible for ONE of the gotos in this code!