revset: point out wrong behavior in fullreposet I cannot fix all issues in revset because I've got other things to do, but let's write down all the brokenness to help other people reading and fixing.

revsetbenchmarks: also display tag when printing a revision This is usually more useful information than the commit message.

revsetbenchmarks: clean up revsets that achieved with default variants We remove revset making use of min and max as this is covered by the variants. We could use variant for roots too, but it is not in the default so keep it here.

revsetbenchmarks: use combination variants in default set Now that we have them, let's make use of them.

revsetbenchmarks: support combining variants with "+" We need more advanced variants in some cases. For example, "The last rev of the sorted version". We introduce a syntax for this: `reverse+last` means `last(reverse(REVSET))`.

revsetbenchmarks: use many more variants by default So far the variants feature was introduced, but not used by default. We now use a set of basic variants by default.

revsetbenchmarks: display even more compact timing result We now use an 8 char display for timing (from 10), we add some logic to drop precision if the number grows too large (as we do not care about sub-0 digit in this case). This allow to pack more variants in a single screen.