Short: New string efun by Doomdark
Date: 981027
State: Patch
Long:
The string efun allows the quick replacement of aliases in strings.
Some testings is needed, but this could be faster than the generic
regreplace.

The other efun (make_string_shared) is better be done as a sefun.
It is better to improve the string-sharing policy of the driver
than to make mudlibs depending on it.

For code, see bugs/doomdark/*
