Make nRF5 example fit better in nRF ecosystem

By making dir hierarchy replicate that of examples provided with the nRF
IoT SDK.

Also, example for Keil uVision IDE is added.

PUBLISHED_FROM=1a3d9a54d15eb1acfb1b5d162138576a387ed21c

examples/nRF52/http/main.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2014-2016 Cesanta Software Limited
+ * All rights reserved
+ */
+
+#include "bleconfig.h"
+#include "myboard.h"
+
+#include "mongoose.h"
+
+/*
+ * This is a callback invoked by Mongoose to signal that a poll is needed soon.
+ * Since we're in a tight polling loop anyway (see below), we don't need to do anything.
+ */
+void mg_lwip_mgr_schedule_poll(struct mg_mgr *mgr) {
+}
+
+
+// Define an event handler function
+void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
+  if (ev == MG_EV_POLL) return;
+  /* printf("ev %d\r\n", ev); */
+  switch (ev) {
+    case MG_EV_ACCEPT: {
+      char addr[32];
+      mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr),
+                          MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+      printf("%p: Connection from %s\r\n", nc, addr);
+      break;
+    }
+    case MG_EV_HTTP_REQUEST: {
+      struct http_message *hm = (struct http_message *) ev_data;
+      char addr[32];
+      mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr),
+                          MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+      printf("%p: %.*s %.*s\r\n", nc, (int) hm->method.len, hm->method.p,
+             (int) hm->uri.len, hm->uri.p);
+      mg_send_response_line(nc, 200,
+                            "Content-Type: text/html\r\n"
+                            "Connection: close");
+      mg_printf(nc,
+                "\r\n<h1>Hello, %s!</h1>\r\n"
+                "You asked for %.*s\r\n",
+                addr, (int) hm->uri.len, hm->uri.p);
+      nc->flags |= MG_F_SEND_AND_CLOSE;
+      LEDS_INVERT(LED_THREE);
+      break;
+    }
+    case MG_EV_CLOSE: {
+      printf("%p: Connection closed\r\n", nc);
+      break;
+    }
+  }
+}
+
+
+/**
+ * @brief Function for application main entry.
+ */
+int main(void)
+{
+
+  cs_log_set_file(stdout);
+
+  bleconfig_init();
+
+  {
+    struct mg_mgr mgr;
+
+    mg_mgr_init(&mgr, NULL);  // Initialize event manager object
+
+    // Note that many connections can be added to a single event manager
+    // Connections can be created at any point, e.g. in event handler function
+    const char *err;
+    struct mg_bind_opts opts;
+    struct mg_connection *nc = NULL;
+    memset(&opts, 0x00, sizeof(opts));
+    opts.error_string = &err;
+    nc = mg_bind_opt(&mgr, "80", ev_handler, opts);  // Create listening connection and add it to the event manager
+    if (nc == NULL) {
+      printf("Failed to create listener: %s\n", err);
+      return 1;
+    }
+    mg_set_protocol_http_websocket(nc);
+
+    for (;;) {  // Start infinite event loop
+      bleconfig_poll();
+      sys_check_timeouts();
+      mg_mgr_poll(&mgr, 0);
+    }
+
+    mg_mgr_free(&mgr);
+    return 0;
+  }
+
+}