Partition code into modules
Remove --sync option

See merge request bortzmeyer/homer!23

Use an underscore '_' in front of the function name.

All the options are now stored in an object.

When using a literal IP address, the IP address is sent as SNI.
This may lead to a `close notify' from the server. Therefore we
decided to catch the OpenSSL error and suggest to use the --nosni
option.