* removed migration notes from the README (now that everything has been migrated)
 * cleaned up http_net (in preparation for adding http_scheduler)
 * added http_scheduler (this can handle multiple http/https connections on multiple servers and multiple http requests)
 * more work on http_net (moved server connect to the constructor, added ssl support, added receive_functor handling, added reconnect), but open_url and check_header are still wip
 * fixed unused flag for "use_gl32_core" in floor
 * in premake.sh: call "sysctl -n" directly on os x and freebsd (instead of piping it through sed)
 * more work on http_net