ConfigFile: avoid warning about trivial range-check on 32bit platforms
lalapps/pulsar: renamed some prototype arguments to avoid warnings

   - apparently, on an old MacOSX-10.5.8 32bit Intel platform with gcc-4.0.1
     I get various warning about prototype argument names shadowing globals
     namely in DriveHoughMulti, HierarchSearchGCT, heterodyne_pulsar.h, TwoSpect
   - this patch trivially fixes this by renaming the prototype arguments
updated and hacked ax_ext.m4 configure macro to latest version

   - fixes --with-simd check crashing on MacOSX-10.5 32bit 'moss' Jenkins platforms
   - updated to latest released version of the ax_ext.m4 script, and then
     applied the suggested fix from https://pm.bsc.es/projects/mcxx/ticket/1201
     (which has now also been moved upstream: https://savannah.gnu.org/patch/index.php?8321)
   - fixes #1227