add filteropener abstraction for store openers

opener: introduce an abstact superclass of it Currently, this class doesn't do anything useful.

graphlog: use a set for inclusion test This makes a big difference in performance in the special case where all revisions are being graphed.

graphmod: restore generator nature of dagwalker 9966c95b8c4f introduced the ability to walk the DAG given arbitrary revisions, but changed the behaviour of it to return a list of all nodes (and create a changectx for each one) rather than doing it lazily. This has a pretty significant impact on performance for large repositories (tested on CPython repo, with output disabled): $ time hg glog real 0m2.642s user 0m2.560s sys 0m0.080s Before 9966c95b8c4f: $ time hg glog real 0m0.143s user 0m0.112s sys 0m0.032s And after this fix: $ time hg glog real 0m0.213s user 0m0.184s sys 0m0.028s

graphlog: log -G --follow file does not work, forbid it We do not have revsets to follow file history.

graphlog: unify log -G revset translation

graphlog: fix log -G --prune follow() revset really means '::.' while we want something based on the passed argument. Also, ancestors() revset does not include the parent revisions.

graphlog: escape log -G single value option arguments

graphlog: fix log -G --removed Current version was mispelled and processed like a valued argument.

graphlog: fix log -G option types when translating to revset For instance, --keyword is a multiple value option while it was processed as a single value option.