sparse: use set for capturing profiles Order doesn't need to be preserved. A set is acceptable. Differential Revision: https://phab.mercurial-scm.org/D95

util: remove dead code which used to be for old python2 versions Differential Revision: https://phab.mercurial-scm.org/D107

status: add a flag to terse the output (issue4119) This adds an experimental flag -t/--terse which will terse the output. The terse flag will respect other flags which filters the output. The flag takes a string whose value can be a subsequence of "marduic" (the order does not matter here.) Ignored files are not considered while tersing unless -i flag is passed or 'i' is there is the terse flag value. The flag is experimental for testing as there may be cases which will produce strange results with the flag. We can set the terse on by default by simply passing 'u' to the cmdutil.tersestatus(). This patch also adds a test file with tests covering the new feature.