minor: fix some pedantic warnings from xlc -qinfo
minor: fix some pedantic warnings from xlc -qinfo

"(I) Redefinition of pause hides previous definition."
pause() function vs pause variable name; fix by renaming variable
so that it does not shadow
xlc supports __builtin_constant_p()
plasma_sysconf - system configuration info

(limited selection of sysconf() info that will likely grow)
Makefile - add new plasma components