Fix more C warnings

Summary: I'm a doofus and didn't do a clean build, thus missing a few
warnings in my earlier cleanup.

mlpderpyhooves

Reviewed By: @ptarjan

Differential Revision: D1375804
Exit server on hhconfig change

Summary: The hhi embedding option is handled at server init time, and
it's going to be more trouble than it's worth IMO to allow runtime
twiddling of it. (Off -> on could probably be made to work, but on ->
off is trickier with current machinery.) So instead, just kill the
server when we detect an hhconfig change; `hh_client` will start it up
again next time.

Reviewed By: @elgenie

Differential Revision: D1376096
Stop ignoring Makefiles in Hack repo

Summary: There's an annoying `Makefile` rule in hphp/.gitignore and it's bitten
me a few times. Let's override it for Hack.

Reviewed By: @jwatzman

Differential Revision: D1364509
Convert ext/memcache to HNI

Summary: Part of #1480
Closes #2795

Reviewed By: @ptarjan

Differential Revision: D1354168

Pulled By: @JoelMarcey
Fix for incorrect pathinfo

Summary: We should only reset the path_info if it doesnt already exist.
Closes #2906

Reviewed By: @ptarjan

Differential Revision: D1377070

Pulled By: @JoelMarcey
FastCGI: Added support for different proxy types in the script_filename string.

Summary: ie: proxy:balancer://host:port/file/name.php and proxy:fcgi://host:port/file/name.php
also converted the 4 comparison strings into statics
Closes #2907

Reviewed By: @fredemmott

Differential Revision: D1377080

Pulled By: @JoelMarcey