02 May 2020 - Make code compatible to Python 3 (losing some backward compatibility)
5.14
19 August 2019 -remove socket setblocking() calls which should be no longer needed, and which may have caused hangups. Thanks: Viacheslav Chimishuk. -correct version number string in error message. Thanks: Piet van Oostrum.
5.13
22 February 2019 -second attempt at fixing SNI change with Python < 2.7. Thanks: "Cimbal".
5.12
22 February 2019 -bugfix: the SNI change broke something else with Python 2.6 and earlier; fixed. Thanks: "Cimbal".
5.11
13 February 2019 -bugfix: the SNI change did not work correctly with Python < 2.7.13; should be fixed now. Thanks: Scott Robbins.