Merge windows code.

Signed-off-by: Sean Ogden <positivelyskewed.sf@gmail.com>
added ifdefs in headers.

Signed-off-by: Sean Ogden <positivelyskewed.sf@gmail.com>
windows merge fixes.

Signed-off-by: Sean Ogden <positivelyskewed.sf@gmail.com>
Merge branch 'windows' of git://github.com/seanogden/po6

* 'windows' of git://github.com/seanogden/po6:
  windows merge fixes.
  added ifdefs in headers.
  Merge windows code.
add osx support

Signed-off-by: Sean Ogden <positivelyskewed.sf@gmail.com>
Merge branch 'osx' of git://github.com/seanogden/po6

* 'osx' of git://github.com/seanogden/po6:
  add osx support
Merge barrier and barrier_portable
Merge branch 'master' into releases/0.3

* master:
  Merge barrier and barrier_portable
  add osx support
  windows merge fixes.
  added ifdefs in headers.
  Merge windows code.
Set version numbers for the 0.3.1 release.