Enabled the calibration to accept a wider range of values

    * include/support.h: If the calibration factor is negative, scale up
        the repeat factor
Fix scaling for blowfish

    * src/blowfish/bf.c: Remove scaling from inside the benchmark
        function (performed in main)
Fix output validation for dijkstra

    * src/dijkstra/dijkstra_small.c: output_count needs to be
        reinitialised for each call to benchmark.
Merge pull request #31 from jpallister/master

Calibration and benchmark fixes