This is a follow-up of the Python 3 port.
The `message` field is no longer supported in standard exceptions.

* Added wrapper to use PYTHON environment variable in tests
* Added unicode comment to default test config
* Changed config objects to use locale encoding
* Changed to use byte buffers for config (re-)writing
* Added tests for unicode sensitive tools

Changed rmexp to show directory sizes and times before removal, fixed handling of quotes in getexp (needed for log and restart dirs in rmexp)

* Added README mode to 'getexp'
* Changed 'getexp' output from warning to info
* Added option to skip directory creation for config tests (--no-make-dirs/-m)
* Support for default configuration settings by model build (SETUP.config)
* Added User Guide

* Logging
** Fixed bailout routine to allow message format arguments
** Explicitly added default warning level for ease of debugging
* Added verbose mode to getexp, showing all top level variable settings
* Fixed template loading to allow out of directory generation (-p, MKEXP_PATH)

* Changed to use argparse library for command line handling
* Added option to set search path for standard configuration (--path)
* Added use of config file comments in namelist files

* Added support for search path to getexp (amends r3166)
* Added support for keyword substitution to default environment (amends r3061)

* Added optional template for namelists (namcouple)
* Added info line for generated files (mkexp_input variable)
* Added model directory to 'getexp' output

* Added missing version keywords in scripts and modules
* Updated some of the header comments

* Added handling of experiment description
** Initial comment is parsed if no EXP_DESCRIPTION is set
** Description is written to script directory as README file
* Added setting of top-level settings from command line

* Changed directories to be fully configurable by default config
* Added tools for diff, printing, removal of experiment/script data