Lightweight points

Lightweight points of libtuv from libuv for IoT

• heap-inl.h: inlining to normal function, this may slow down but can reduce code size
• remove async nature and run in blocking mode
  • with not much concurrent connection to handle we may run in sync mode
  • maybe can remove threadpool, async, io, threadpool, thread
• events array size in uv__io_poll to reduce stack size
  • size is 1024 for linux which becomes 12KB or 16KB in linux, but can be relatively quite large for embedded systems

void uv__io_poll(uv_loop_t* loop, int timeout) {
  static int no_epoll_pwait;
  static int no_epoll_wait;
  struct uv__epoll_event events[TUV_POLL_EVENTS_SIZE];
  struct uv__epoll_event* pe;
  struct uv__epoll_event e;

• and...