* read_poll uses random_poll until the pool is filled.  This is ian
  issue at first initialization, as this requries POOLSIZE good random (level 1 from
  gather_random) even in level 0 and 1.
  For now, the code is only applied to level 2.  Eventually, readable_pool
  should be fixed to return 0 if initialization is not done yet and not enough bytes
  are available.  Otherwise it enters an infinite loop.

* Permissions?

* Off by one error in gather_random/io_write?  I can only get GATHERBUFSIZE - 1
  bytes from it.