Avoid collisions between parallel installations of Cygwin

[Dave Korn]

Charles Wilson wrote:

> ...unless the magic ID strings themselves were also each part of the
> struct.  

  I must admit I took that as read; as you say, any technique relying on a
fixed memory offset between separate C language-level data objects is doomed
to fail sooner or later, but if the string is included as constant data in the
struct and we're only modifying one struct in-place which obeys known and
predictable layout rules imposed by the compiler, we'll be OK.

> We'd LIKE to be able to "switch" its mode without recompiling, and this
> last bit is the tail wagging the dog here.  Sure, a general approach to
> .rsrc-style resources in the cygwin1.dll is nice -- but is it necessary?

  It's an absolutely standard mechanism in all win32 executables everywhere,
of which the cygwin dll is one; I see no reason to not use it on any kind of
principle.

  I did think this overall change wasn't intended to go in until after the
release, though?

    cheers,
      DaveK