[parameters.base] bugfix
[parameters.base] ensure alphanumerical order in ParameterType.iter...
[parameter.base] small tweak
[parameters.base] remove obsolete parameter_info() method
[parameters.base] move parse_parameter_type into ParameterType's __init__
[parameters.base] bugfixes
[parameters.base] some tweaks to ParameterType
[parameters.base] move global parse_parameter() to Parameter
[parameters.base] refactor implementation of parse_parameter()