[engines] MicroArchBenchmark: add a real log message before marking comb as done or cancel
[engine] vm5k_engine: add a cache mechanism for cpu_topology
[engines] Add the use of the new cache in cpu_topology
[engines] MicroArchBenchmark: Add the core number to the kflops output file
[engines] vm5k_engine: add some import for file manipulation
[engines] MicroArchBenchmark: remove files from comb_dir before retrieving comb files results, correct the vms definition if vm_multi does not exists, add some error message