Make mcuboot less mynewt style

Remove most of mynewt specific stuff to a separate port package. This
should make mcuboot less "mynewt'y" and slightly easier to port to.

- Mynewt specific stuff moved to boot/mynewt.
- Sample app moved from apps/boot to boot/mynewt.
- Use MYNEWT_VAL macro only on mynewt port.
- BOOTUTIL_* and MYNEWT_VAL() usage moved to MCUBOOT_ defines.
diff --git a/boot/mynewt/src/main.c b/boot/mynewt/src/main.c
new file mode 100755
index 0000000..9cf4737
--- /dev/null
+++ b/boot/mynewt/src/main.c
@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <assert.h>
+#include <stddef.h>
+#include <inttypes.h>
+#include "syscfg/syscfg.h"
+#include <flash_map/flash_map.h>
+#include <os/os.h>
+#include <bsp/bsp.h>
+#include <hal/hal_bsp.h>
+#include <hal/hal_system.h>
+#include <hal/hal_flash.h>
+#ifdef MCUBOOT_SERIAL
+#include <hal/hal_gpio.h>
+#include <boot_serial/boot_serial.h>
+#include <sysinit/sysinit.h>
+#endif
+#include <console/console.h>
+#include "bootutil/image.h"
+#include "bootutil/bootutil.h"
+
+#define BOOT_AREA_DESC_MAX  (256)
+#define AREA_DESC_MAX       (BOOT_AREA_DESC_MAX)
+
+#ifdef MCUBOOT_SERIAL
+#define BOOT_SER_CONS_INPUT         128
+#endif
+
+int
+main(void)
+{
+    struct boot_rsp rsp;
+    int rc;
+
+#ifdef MCUBOOT_SERIAL
+    sysinit();
+#else
+    flash_map_init();
+    hal_bsp_init();
+#endif
+
+#ifdef MCUBOOT_SERIAL
+    /*
+     * Configure a GPIO as input, and compare it against expected value.
+     * If it matches, await for download commands from serial.
+     */
+    hal_gpio_init_in(BOOT_SERIAL_DETECT_PIN, BOOT_SERIAL_DETECT_PIN_CFG);
+    if (hal_gpio_read(BOOT_SERIAL_DETECT_PIN) == BOOT_SERIAL_DETECT_PIN_VAL) {
+        boot_serial_start(BOOT_SER_CONS_INPUT);
+        assert(0);
+    }
+#endif
+    rc = boot_go(&rsp);
+    assert(rc == 0);
+
+    hal_system_start((void *)(rsp.br_image_addr + rsp.br_hdr->ih_hdr_size));
+
+    return 0;
+}