Add prefix inter_guild_ to most functions in int_guild.c
Add prefix inter_mail_ to most functions in int_mail.c
Add prefix inter_mercenary_ to most functions in int_mercenary.c
Add prefix inter_party_ to most functions in int_party.c
Add prefix inter_storage_ to most functions in int_storage.c
Add prefix inter_ to most functions in inter.c
Add prefix pincode_ to global variables in pincode.c