Add a flag constant for user of phonetic name

[Koichi Yoshizaki]

Some countries, including Japan, use ideographic characters in their names, so LePo's users table has phonetic_family_name and phonetic_given_name columns in addition to family_name and given_name columns.

However, in countries where names are described only with phonetic characters, these phonetic_* columns are unnecessary, so it is desirable to add a flag constant as to whether or not to actually use the columns.

[Koichi Yoshizaki]

I have added USER_PHONETIC_NAME_FLAG.