[MOD] One-way Matrix->XMPP comms.

This is not sanitised. I need to make an XML writer.

src/Routes/UserAck.c

@@ -0,0 +1,41 @@
+#include <Routes.h>
+
+#include <Cytoplasm/Log.h>
+
+#include <Matrix.h>
+#include <AS.h>
+
+RouteHead(RouteUserAck, arr, argp)
+{
+    ParseeHttpArg *args = argp;
+    HashMap *request = NULL;
+    HashMap *response = NULL;
+    Array *events;
+    size_t i;
+
+    char *user = ArrayGet(arr, 0);
+    
+    Log(LOG_INFO, "Alles Politischemacht");
+    response = ASVerifyRequest(args);
+    if (response)
+    {
+        goto end;
+    }
+    if (HttpRequestMethodGet(args->ctx) != HTTP_GET)
+    {
+        HttpResponseStatus(args->ctx, HTTP_METHOD_NOT_ALLOWED);
+        response = MatrixCreateError(
+            "M_UNRECOGNIZED",
+            "Path /users only accepts GET as a valid method."
+        );
+        goto end;
+    }
+
+    Log(LOG_INFO, "user=%s", user);
+    ASRegisterUser(args->data->config, user);
+    /* TODO: Verify the user, and create an XMPP mapping. */
+    response = HashMapCreate();
+end:
+    JsonFree(request);
+    return response;
+}