[gdal-dev] Separate the debug and the optimized windows builds

[Tamas Szekeres]

Folks,

I've made an attempt to separate the debug builds from the optimized
configurations for the windows compilations.
Currently we had to make several changes manually to make a consistent
build since we had to change between the OPTFLAGS
settings in makefile.vc as well as change the /debug linker option in
a number of the subsequent makefiles. (It should also be noted that
many of these have used predefinied /debug settings regardless of that
we do optimized builds)

I've made a change in the makefiles that this switch depends on a
common DEBUG setting that can be definied at the command line, like

nmake -f makefile.vc DEBUG=YES

Let me know if you have issues related to this change, though it seems
a trivial addition.

Best regards,

Tamas