Comment 4 for bug 679035

Lukas fixed it so the setting is written to the Makefile, this ensures that enblend/enfuse use the correct temp location for cache files.

What hasn't been fixed is that the temporary .pto file that is created for stitching has internal paths set for creating intermediate TIFF files that are deleted later - My understanding is that the location of these TIFF files isn't effected by the tempdir preference setting, but is only effected by the $TEMP environment setting.