Because the Hs2Py constant generation infrastructure is transitional,
there are two generated 'autoconf' modules, namely, 'src/AutoConf.hs'
and 'lib/_autoconf.py'.  However, conflicting values were being
generated for Haskell and Python concerning the variables
'OS_SEARCH_PATH', 'ES_SEARCH_PATH', and 'IALLOCATOR_SEARCH_PATH'.
This patch fixes this problem by placing these variables only on the
Haskell side and generate Python constants holding the correct value.

Signed-off-by: Jose A. Lopes <jabolopes@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>