fault.h - add cpp guards
fault.h - add cpp guards

For some compilers, some of the routines we're redefining are already
really #defined, so #undef them first if needed.

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