ensure core mutex created in recursive mode, forces use of -lpthread

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk/proj@2339 4e78687f-474d-0410-85f9-8d5e500ac6b2
refresh from configure.in

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk/proj@2340 4e78687f-474d-0410-85f9-8d5e500ac6b2
fix unused variable warnings in healpix

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk/proj@2341 4e78687f-474d-0410-85f9-8d5e500ac6b2
use PTHREAD_MUTEX_RECURSIVE_NP on pre-unix98 systems instead of PTHREAD_MUTEX_RECURSIVE

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk/proj@2342 4e78687f-474d-0410-85f9-8d5e500ac6b2