Fix signed vs unsigned issues in Perl PMDA interface, which made checking for null indom problematic.  Also fix the already-seen cluster index lookup for value refresh callbacks.
Fix signed vs unsigned issues in Perl PMDA interface, which made
checking for null indom problematic.  Also fix the already-seen
cluster index lookup for value refresh callbacks.

edwardt/pcp,edwardt/pcp,andyvand/cygpcpfans,ryandoyle/pcp_original,tjanez/pcp,mbaldessari/pcp,ryandoyle/pcp_original,aeg-aeg/pcpfans,aeg-aeg/pcpfans,edwardt/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,prasincs/pcp,tjanez/pcp,aeg-aeg/pcpfans,adfernandes/pcp,prasincs/pcp,andyvand/cygpcpfans,wuliming/pcp,tjanez/pcp,ryandoyle/pcp_original,prasincs/pcp,prasincs/pcp,tjanez/pcp,andyvand/cygpcpfans,andyvand/cygpcpfans,edwardt/pcp,aeg-aeg/pcpfans,aeg-aeg/pcpfans,wuliming/pcp,aeg-aeg/pcpfans,aeg-aeg/pcpfans,wuliming/pcp,prasincs/pcp,prasincs/pcp,edwardt/pcp,ryandoyle/pcp_original,mbaldessari/pcp,tjanez/pcp,edwardt/pcp,wuliming/pcp,prasincs/pcp,aeg-aeg/pcpfans,mbaldessari/pcp,edwardt/pcp,mbaldessari/pcp,andyvand/cygpcpfans,ryandoyle/pcp_original,prasincs/pcp,andyvand/cygpcpfans,adfernandes/pcp,edwardt/pcp,adfernandes/pcp,wuliming/pcp,wuliming/pcp,tjanez/pcp,adfernandes/pcp,ryandoyle/pcp_original,ryandoyle/pcp_original,tjanez/pcp,wuliming/pcp,ryandoyle/pcp_original,adfernandes/pcp,andyvand/cygpcpfans,mbaldessari/pcp,mbaldessari/pcp,wuliming/pcp,tjanez/pcp,andyvand/cygpcpfans