nopoll: * [fix] Corrected nopoll_conn_flush_writes documentation (wrong time indication   and explain better reported values).
nopoll:
* [fix] Corrected nopoll_conn_flush_writes documentation (wrong time indication
  and explain better reported values).

* [fix] Making nopoll_conn_flush_writes to also check for EWOULD_EINPROGRESS to
  avoid insisting.

* [fix] Making nopoll_conn_send_frame to clear conn->pending_write_added_header 
  to 0 when it is detected enough was written to include the header so calls to
  nopoll_conn_flush_writes do not reporting bytes (user land) considering those
  bytes twice. 

ASPLes/nopoll,schmidtw/nopoll,ASPLes/nopoll,schmidtw/nopoll,ASPLes/nopoll,schmidtw/nopoll,schmidtw/nopoll,ASPLes/nopoll,ASPLes/nopoll,ASPLes/nopoll,schmidtw/nopoll,schmidtw/nopoll