String references

Working with STRREFs.

REPLACE_STRREF_TRA patch

Reads an strref at the given offset. In the string, replaces occurences of old_substring_traref with new_substring_traref. SAYs the new string back to the offset.

INT_VAR	Description	Type	Default
new_substring_traref	traref of replacement text	int	required
offset	strref offset	int	required
old_substring_traref	traref of text to be replaced	int	required