Log Message:
Update to 2.0.0, supplied by skrll@netbsd.
Changes:
   *) Make pth_poll(3) more compliant to POSIX.1-2001/SUSv3 poll(2).
   *) Make pth_select(3) more compliant to POSIX.1-2001/SUSv3 select(2).
   *) Replaced pth_event_occurred() with pth_event_status().
   *) Add Autoconf option --with-fdsetsize=NUM for enlarging FD_SETSIZE.
   *) Added thread attribute PTH_ATTR_DISPATCHES.
   *) Added sub-API pth_uctx_* for user-space context switching.
   *) Add a Pth variant of the new POSIX pselect(2) function.
   *) Internally cleaned up the error handling macros.
   *) Added POSIX-compliant sanity checks for bad fds.
   *) Added pth_nanosleep() function.
   *) Allow a NULL name for pth_msgport_create()
   *) Completely rewrote the "hard syscall mapping".
   *) Added support to pth_poll(3) for POLLD{RD,WR}{NORM,BAND}.
   *) Fixed a long-standing termination bug in pth_exit(3).
   *) Upgraded to Autoconf 2.57, Shtool 1.6.2 and Libtool 1.4.3.
   *) Add optional support for OSSP ex based exception handling.