Add autoconf checks for pthreads; fix #340

setup.sh

@@ -9,7 +9,9 @@
 
 if [ "clean" == "$1" ]; then
   make distclean || echo "continuing..."
-  rm -rf tmp autom4te.cache config
+  find config/m4 -type f \( -name libtool\* -o -name lt\* \) | xargs rm -f
+  find config -name m4 -prune -o -type f -print | xargs rm -f
+  rm -rf tmp autom4te.cache
   rm -f INSTALL Makefile.in aclocal.m4 configure config.h.in ChangeLog
   rm -f jv_utf8_tables.gen.h lexer.c lexer.h parser.c parser.h
 elif [ "superclean" == "$1" ]; then