Fixes issue #19 - Added a list_to_string converter, added related unit tests.
Merge pull request #20 from AdrianGaudebert/19-list-to-string-converter

Fixes issue #19 - Added a list_to_string converter for lists and tuples.
added deepcopy to avoid problem where duplicate class requirements appear multiple times in a namespace
adding option to pass exclude_from_print_conf and exclude_from_dump_conf to add_option(), r=twobraids
added class lists with namespaces.  moved required config to it own file to avoid recursive imports
changed get_required_config to return a Namespace rather than a raw dict type
fixed aggregation bug and enhanced class_list converter
added a search algorithm to the DotDict class
added support for configobj
fixed dotdict to fail with KeyError on unknown keys that start with __, r=twobraids
enhanced configobj have an include directive
more tests of includes
made +includes load relative to original ini file
Merge pull request #37 from twobraids/includes

enhanced configobj have an include directive
class_converter whitespace independent, r=lars
eliminated special handling of 'application' config option
fixes bug where zero length file if created when
attempting a config file write with an unregistered suffix
set_default to allow redefining defaults in Options
changes to RequiredConfig to allow derived classes to
override options defined in parent classes.
fix for short_form thing on aggregates, r=twobraids
added missing dict type to converters