v1.9-pre

• Renamed UCS_ERR_REMOTE_DISCONNECTED to UCS_ERR_CONNECTION_RESET
• Merged several RoCE LAG fixes
• Use these to enable RoCE LAG for small messages:

  export UCX_MAX_EAGER_LANES=2
  export UCX_IB_SEG_SIZE=2k
  

• Make sure the following is passed to ucp_ep_create():

   ep_params.field_mask      |= UCP_EP_PARAM_FIELD_ERR_HANDLER |
                                UCP_EP_PARAM_FIELD_ERR_HANDLING_MODE;
   ep_params.err_mode         = UCP_ERR_HANDLING_MODE_PEER;
   ep_params.err_handler.cb   = error_handler;
   ep_params.err_handler.arg  = reinterpret_cast<void*>(this);