what was adopted in tzcode95c to solve the problem of the first char
detzcode() extracts requiring sign extention (this is needed for
machines with 64 bit longs).
Our implementation is a bit more efficent, but requires a new macro,
SIGN_EXTEND_CHAR(), and a conditional to set it appropriately).
One minor enhancement for machines without ANSI compilers that have 32
bit longs would be to define SIGN_EXTEND_CHAR() to be the identity
macro.
On the other hand, it makes it easier to track the master tzcode sources
if we try to keep the distribution together as much as possible.
The zic and zdump commands will access the files the need with make's
.PATH facility.
