minor: lenght -> length
call bson_realloc in bson_realloc_ctx
__bson_uint32_swap_slow should not use long values
strerror_r 0 for success
compute time in micro seconds not in nano seconds
fix implementation and use of bson_strerror_r

o we weren't correctly returning a possibly static string from
  bson_strerror_r.

o we're supposed to use the return value from strerror_r, not just
  assume that the passed in buf was filled
Merge pull request #94 from jeromelebel/__bson_uint32_swap_slow_no_long

__bson_uint32_swap_slow should not use long values
Merge pull request #96 from jeromelebel/strerror_r_returns_0_for_success

strerror_r 0 for success
b64_ntop should return ssize_t
Merge pull request #97 from jeromelebel/nano_seconds_problem

compute time in micro seconds not in nano seconds
no need for casting
Merge pull request #99 from jeromelebel/b64_ntop_return_ssize_t

b64_ntop should return ssize_t
Merge branch 'master' of github.com:mongodb/libbson into development