Attempt to catch some dup2 behavior we're particularly interested in.
Attempt to catch some dup2 behavior we're particularly interested in.

* Somehow application tries to make a duplicate of an fd that
  we are using internally (protected).  Shouldn't happen.

* Application tries to duplicate an fd it knows about into
  one that we're protecting.  May happen, log warning.

dtzWill/ipcopter,dtzWill/ipcopter,dtzWill/ipcopter,dtzWill/ipcopter,dtzWill/ipcopter,dtzWill/ipcopter