Added slre benchmark

    * Makefile.am: Added slre benchmark
    * Makefile.in: Regenerated
    * configure: Regenerated
    * configure.ac: Added slre benchmark
    * src/slre/Makefile.am: Added slre benchmark
    * src/slre/Makefile.in: Regenerated
    * src/slre/slre.c: Added slre benchmark
    * src/slre/slre.h: Added slre benchmark