Make preliminary Seasocks server with data collector.

This is stage 2 of the http_status project!
Currently, this version can display various things from the queues in
a web browser, but only in plain text. It implements some of the basic
classes that will later be used for later stages. It also supports
concurrent connections.

A couple of things not included are all the trigger/bandwidth adjust
options.

Change-Id: I108d965a768c073a0f4b3757c0475fe7bfc34ccb
diff --git a/aos/build/externals.gyp b/aos/build/externals.gyp
index 2bfe241..c4bbaa2 100644
--- a/aos/build/externals.gyp
+++ b/aos/build/externals.gyp
@@ -207,6 +207,12 @@
           '<(AOS)/externals/seasocks',
           '<(externals)/seasocks-<(seasocks_version)/src/main/c',
         ],
+        'cflags': [
+          # Since seasocks/WebSocket.h has functions implemented that don't use
+          # their parameters, the compilation of http_status would fail without
+          # the following exception.
+          '-Wno-unused-parameter',
+        ],
       },
     },
   ],