Enable mpu stack for latest zephyr to enable app manager (#673)

And output detail info when install wasm app failed, update document and fix some compile warnings and errors.

Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>

test-tools/host-tool/src/main.c

@@ -750,7 +750,7 @@ static void output_event(request_t *obj)
 
 int main(int argc, char *argv[])
 {
-    int ret;
+    int ret = -1;
     imrt_link_recv_context_t recv_ctx = { 0 };
     char buffer[BUF_SIZE] = { 0 };
     uint32_t last_check = 0, total_elpased_ms = 0;