Modified configure.ac to work with old versions of autotools

    * Makefile.in: Regenerated
    * aclocal.m4: Regenerated
    * configure: Regenerated
    * configure.ac: Older versions of autotools do work
    * src/2dfir/Makefile.in: Regenerated
    * src/blowfish/Makefile.in: Regenerated
    * src/crc32/Makefile.in: Regenerated
    * src/cubic/Makefile.in: Regenerated
    * src/dijkstra/Makefile.in: Regenerated
    * src/fdct/Makefile.in: Regenerated
    * src/float_matmult/Makefile.am: Regenerated
    * src/float_matmult/Makefile.in: Regenerated
    * src/int_matmult/Makefile.in: Regenerated
    * src/platformcode/Makefile.in: Regenerated
    * src/rijndael/Makefile.in: Regenerated
    * src/sha/Makefile.in: Regenerated
    * src/template/Makefile.in: Regenerated