#146 Don’t format small sizes as kB.
#146 Don’t format small sizes as kB.

* Don’t format small sizes as kB.

Currently byte sizes are always shown with a kb approximation. This is not helpful for  small sizes, e.g. 5 bytes (~0 kb). Instead leave out the kb approximation for sizes < 1kB. Also:
- change from kb (kilobit) to kB (kilobyte)
- show as MB for sizes >= 1MB
- don’t use decimals for approximate sizes < 1MB. The difference between e.g. 67 kB and 68 kB is small, and integer sizes are more glanceable.

* Don’t format small sizes as kB.

Currently byte sizes are always shown with a kb approximation. This is not helpful for  small sizes, e.g. 5 bytes (~0 kb). Instead leave out the kb approximation for sizes < 1kB. Also:
- change from kb (kilobit) to kB (kilobyte)
- show as MB for sizes >= 1MB
- don’t use decimals for approximate sizes < 1MB. The difference between e.g. 67 kB and 68 kB is small, and integer sizes are more glanceable.

micmro/PerfCascade,micmro/PerfCascade,micmro/PerfCascade,micmro/PerfCascade