Add missing doc

[tyru]

Add the following doc.
ref. #440

• Mapping.execute_abbr_command()
• Mapping.execute_map_command()
• Mapping.execute_unmap_command()
• Mapping.get_abbr_command()
• Mapping.get_all_modes()
• Mapping.get_all_modes_list()
• Mapping.get_map_command()
• Mapping.get_unabbr_command()
• Mapping.get_unmap_command()
• Mapping.is_mode_char()
• Mapping.options_chars2dict()
• Mapping.options_chars2raw()
• Mapping.options_dict2chars()
• Mapping.options_dict2raw()
• Web.URI.clone_pattern_set()
• Web.URI.HTTP.canonicalize()
• Web.URI.HTTP.default_port()
• Web.URI.HTTPS.canonicalize()
• Web.URI.HTTPS.default_port()
• Data.String.strchars()

[thinca]

以下全て、タグに Vital. がないです。

[tyru]

oh... 修正しました