commented out the HHC_LOCATION line, as there are no easy to use alternatives for

commented out the HHC_LOCATION line, as there are no easy to use alternatives for
hhc.exe on linux.
we should either run the chm build on a windows box(maybe on the replacement of oti1),
or look into running it through wine see
http://cweiske.de/tagebuch/Generating%20CHM%20files%20with%20Wine%20on%20a%20Linux%20server,%20and%20a%20bit%20about%20PEAR's%20PhD%20transition.htm
for details.
I also set DOT_CLEANUP to NO as the doc generation was spitting out errors regarding some dot
file cannot be found.