fixes assert on win32.

This commit message serves to show how disappointed i am with clang trying
to simply be compatibile with gcc and doing a horrible job of it.

GCC forever.

bson_from_json support

we've had a bunch of internal changes, so lets go ahead and bump this
again.

More win32 compat for the mongo c driver

Removing bson_*_t types.  Providing a shim for stdint instead

some more win32 compat where needed

Support for bson generation from json via yajl

o bson_json_reader_t interface for streaming json parsing
o bson_from_json convenience wrapper
o json-to-bson example program

Supports the full set of strict extended json, at least theoretically

Added missing header for OS X