tor/changes/bug2328

  o Minor bugfixes
    - Fix a bug where we would declare that we had run out of virtual
      addresses when the address space was only half-exhausted.  Bugfix
      on 0.1.2.1-alpha.
    - Correctly handle the case where AutomapHostsOnResolve is set but no
      virtual addresses are available.  Fixes bug2328, bugfix on
      0.1.2.1-alpha.  Bug found by doorss.
    - Correctly handle wrapping around to when we run out of virtual address
      space.  Found by cypherpunks, bugfix on 0.2.0.5-alpha.