HPUX: Put __HP_CURSES back in

HPUX: Put __HP_CURSES back in

We need __HP_CURSES to be defined in order to get the _maxx WINDOW*
field among other things. Define it on HPUX again (it was taken out as
part of 4a6a00d6f45bd0ac94e2eb05adee41552073643a).

Reviewed-on: http://gerrit.openafs.org/3582
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 1bc23299720fc57dfefbb588f1f3de0ec792e069)

Change-Id: Iae7294b266446da8d8577ddf68449d3a12784316
Reviewed-on: http://gerrit.openafs.org/4092
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Andrew Deason <adeason@sinenomine.net>