Calls print_character to print the character at (HL), advances HL, and loops until a byte with bit 7 set (the string terminator) is printed.

This and print_character were previously misclassified as part of the FC29 text data block -- the text ends at $FD96; see that block's header.

Used by the routines at insert_high_score_entry, run_title_screen, options_menu_driver and redefine_keys_screen.