Refactor rename error_500_cms_response to internal_server_error_cms_response
Added bad_request_error_cms_response
Updated code example to use the new internal_server_error_cms_response instead of error_500_cms_response class.
Removed class error_500_cms_response.

Updated cms setup and configuration design:
  Removed CMS_SETUP.configuration: CMS_CONFIGURATION
  Removed CMS_CONFIGURATION and replaced it by using the configuration library.
  Added CMS_DEFAULT_SETUP.configuration: CONFIG_READER
  Addec CMS_SETUP.text_item (name): detachable READABLE_STRING_32 ...
    in order to access option not publish by the CMS_SETUP interface.
Removed CMS_SERVICE.configuration: CMS_CONFIGURATION since it was not used.

Moved configuration library from eiffel-lang to cms libraries.
Fixed issue related to ini config when parsing from string content,
  and also issue related to section included in file via @include.
Updated cms setup and configuration design:
  Removed CMS_SETUP.configuration: CMS_CONFIGURATION
  Removed CMS_CONFIGURATION and replaced it by using the configuration library.
  Added CMS_DEFAULT_SETUP.configuration: CONFIG_READER
  Addec CMS_SETUP.text_item (name): detachable READABLE_STRING_32 ...
    in order to access option not publish by the CMS_SETUP interface.
Removed CMS_SERVICE.configuration: CMS_CONFIGURATION since it was not used.
Improved the email service and related.