github_base.DictConfigParser: Merge sections appearing multiple times
github_base: simplify extract_repo_from_issue
github(_base): add comments
github: clean up imports
cli.switches: move prefilling of self.arguments to Command.__init__

instead of patching Command.__init__ from add_argument_switches we set
an attribute __add_argument_switches__ on Command and do all the
preparation for self.arguments directly from Command.__init__.
add_argument_switches: rename arguments

name     -> keyname
flagname -> swname and looses its "--" prefix.
type     -> argtype
tests: recursive_config_parser is replaced by dict_config_parser
add_argument_switches: fix and simplify treating of default values
cli: Add comments to everything but explicit Commands
cli: Add comments to subcommands