update libuv and http-parser versions

Changes necessary to bump to joyent/http-parser v2.2 and joyent/libuv to v0.10.21

There are 3 failing tests, but they seem to be failing before my changes anyways:
```
=====================================================================
FAILED TEST SUMMARY
---------------------------------------------------------------------
Check for uv_queue_work [tests/800-uv_queue_work.phpt]
Check for uv_chdir [tests/999-uv_chdir.phpt]
Check for uv_cwd [tests/999-uv_cwd.phpt]
=====================================================================
```

Also, sorry for the all the newline changes in `README.md`, my editor strips whitespace. I can try to revert these changes if you'd rather they not be in here.