performance enhancements for cygwin make

[Noel Grandin]

Can't be completely sure because I'm struggling to get the current 
master to build on Windows, but from some cursory testing, I'm not 
seeing much (if any) use of cp and touch in the offapi makefile.

On the other hand, cygpath, mktemp and echo get called a lot.

On 2012-03-13 14:36, Michael Meeks wrote:
> Hi Noel,
>
> On Mon, 2012-03-12 at 11:06 +0200, Noel Grandin wrote:
>> As this point in time, my opinion is that the idea is not worth doing -
>> things like touch and cp don't actually seem to trigger very often in
>> our build process. (Unless I'm doing something very wrong).
> 	Oh ! :-) so - of course, in 'offapi' they prolly do that quite  a lot,
> did you play with 'from clean' make timings in there ?
>
> 	ATB,
>
> 		Michael.
>