Added option -Fi, which allows an arithmetic comparison of headers
with an integer value.
Added shortcut option -Ht, to show sets of a specific type.
Added shortcut option -Hr, to match on the number of revisions.
Added shortcut option -Hs, to match on the size in memory.
Added shortcut option -Hv, to match on the revision value.
Speed up processing if members are not to be displayed or counted.
Worked on formatting of the help text.
Update README.md
Bump version to 2.1
Merge branch 'master' of https://github.com/AllKind/ipset_list