The logging module is no longer required to get diagnostic output
since we use `stderr` by default regardless of the logging module.
Which means that the logging module will only give a more verbose
output than is necessary.
Client.is_logged_in checking is no longer necessary since all HTTP
request handling now raise an exception if they fail so those chunks
are also gone.
Without setting up the logging module, a god number of error conditions
and warnings will never be output by the library. This is a common
pitfall to forget and it's not documented good enough the consequences
of not setting up the logging module when developing applications with
this library.
Check and handle login failure in the examples provided for using this
library. This is a common error condition that should be handled by any
script using this library.
