SERVER-1120 OpenBSD Port

This patch should enable building on OpenBSD 5.4.

- added a processinfo implementation based heavily off of the same
  code for freebsd.
- fixed a few scons problems in mongo and v8
- added __openbsd__ directives to s2 build
- Don't disturb bswap() functions on freebsd.
- Fixed indentation sloppiness. No code changes.

Signed-off-by: Mark Benvenuto <mark.benvenuto@mongodb.com>
SERVER-13638: remove friend access to NamespaceDetails from record store impls
SERVER-13638: record stores don't call DiskLoc::writing
SERVER-13638: RecordStore uses smaller ExtentManager api