sort nodes before outputting so that the output of capnp is somewhat stable
add more build artifacts to gitignore
fixup capnp-test.sh to run on windows
allow backslash as a path separator for relative plugin paths
CreateProcess requires that the working directory is not relative
capnpc encode output is binary
strip \r\n from FormatMessage supplied error string
add KJ_SYSCALL wrappers to stream::setBinary
capnp compile shouldn't have blank lines between errors
fixup stringify for uint64, int64, and floats

- _snprintf was outputting 1e020 instead of 1e20.
- uint64/int64 was using the wrong format specifier. It now uses PRId64
  and friends from inttypes.h.
Only add winsock link for windows
update gtest patch for mingw fixes