RESDIR 1.01: Dynamically write the current directory into GEM.RSC

[New in v1.01: Changed put_string() to use long arithmetic. This seems to
have fixed an integer overflow problem when the new path is shorter than the
existing one.]

As written, the GEM AES relies on hardcoded paths in GEM.RSC, and by default 
these paths point at \GEMAPPS and \GEMAPPS\GEMSYS. This causes trouble if GEM 
is installed in a different directory.

RESDIR alters these paths to point to the current directory. It can either be
run at install time, or at run time.

Syntax is:

RESDIR oldgem.RSC newgem.RSC

For example, if you have a GEM.BAT that reads

C:
CD \GEMAPPS\GEMSYS
GEMVDI

you could change it to read

C:
CD \GEMAPPS2\GEMSYS2
RESDIR GEM.RS0 GEM.RSC
GEMVDI

(having previously made a copy of GEM.RSC called GEM.RS0).

Note that RESDIR relies on the file it's reading (GEM.RS0 in this case) being
an unaltered copy of GEM.RSC; it won't work on files that already point 
somewhere else.

RESDIR is distributed under the GNU GPL. The actual engine of it (TAMPER.C/H)
is capable of reading and writing any FREESTRING resource in any .RSC file;
the main() function in RESDIR.C uses this to set up paths correctly.
