Refactoring result module.

[jkawamoto]

This pull request includes the following updates;

• Update for-loop to use dictionary's value method to reduce referring items,
• Constant strings in print_summary are moved to private constants as the result it has
  • _SDPT3_POS_STATUS_MAP_VERB,
  • _SDPT3_NEG_STATYS_MAP_VERB,
• Update format of long strings to fix pylint's issue, line too long,
• Replace regexes to raw strings in order to fix pylint's issue, anomalous backslash in string,
• Catch TypeError and ValueError in handle_msg_item instead of catching all exceptions,
• Fix pylint's issue: Redefinition of x type from float to int in handle_msg_item.