revsetbenchmarks: use a more compact output format with a header We change the output from: revset #0: draft() 0) wall 0.011989 comb 0.010000 user 0.000000 sys 0.010000 (best of 177) 1) wall 0.012226 comb 0.010000 user 0.000000 sys 0.010000 (best of 193) 2) wall 0.011838 comb 0.020000 user 0.000000 sys 0.020000 (best of 208) to: revset #0: draft() wall comb user sys count 0) 0.012028 0.010000 0.000000 0.010000 170 1) 0.012218 0.010000 0.000000 0.010000 157 2) 0.012622 0.010000 0.000000 0.010000 189 This opens the road to more useful output.