stdbool.h: Move to sys/sys

It's bad style for the kernel to use the same headers as userland
programs.

Requested-by: dillon
kernel: don't allow proplib to redefine bool
libc/stdlib : revert to dragonfly implementation

 * Revert to 2d5c7e410ffcb72d10994a0d1d324b7265e29647. The dragonfly
   version shares code for the various functions of the strtol familly,
   using macros.

 * add locale aware version for the functions the strtol familly. Only
   isspace calls are concerned.
stdlib/libc : don't bring back DragonFly cvs ids
hammer2 - cleanup, write path work

* Code synchronous and asynchronous b*write() in the write path based on
  request flags, instead of just using bdwrite().

* Document a bunch of stuff.

* Remove dead code.
kernel - Fix a SMP race in the 64-bit pmap code

* Some of the pmap code was assuming that pv_entry's would remain stable
  under circumstance where they might not actually remain stable.

  Specifically, when the vm_page spinlock is held while issuing a
  pv_hold_try() call on the pv, the pv is not necessarily stable
  and its pmap and pindex must be double-checked after a successful
  lock is acquired.  This case occurs in two places in the code.

* Do this check in all cases (when the pmap spinlock OR the vm_page spin
  lock is used to access a pv_entry), just to be sure that we have covered
  all the bases.

* This SMP race is virtually impossible to reproduce on 8-thread boxes
  but appears to be easy to reproduce on monster (48-way opteron).

* As of this commit it is not 100% clear if the patch fixes the assertion
  seen, but it probably fixes some things.

  panic: bad *ptep 000000078592b425 sva 00007ffffffff000 pte_pv NULL

Reported-by: ftigeot