Gcc8fixes

These fixes restore most of lalsuite to compilable status with gcc 8. lalinference, lalpulsar, and lalapps are still uncompilable, but enough of lalsuite is compilable to allow gstlal to be built on systems with the latest gcc compilers. This is sort of critical because, well, gstlal is currently unusable on systems with up-to-date gcc compilers, and because gstlal developers work on such systems the inability to compile lalsuite is impeding preparations for the upcoming OPA.