HHVM 3 build error

So I ran into a few problems getting it to run with HHVM 3.2:
- HHVM expected uv.php to begin with `ext_`, which was causing cmake to fail
- `RuntimeOption::ThrowBadTypeExceptions` seems to have been removed (getTyped has default arguments)
- In `tcp.php` the response was not getting sent with Connection: keep-alive. Looks like it needed [uv_close](https://gist.github.com/utaal/1195428#file-webserver-c-L63), but I may have misunderstood the code, however in a quick test it worked with both Connection: close and keep-alive