obsolete: stop doing membership test on list According to the Surgeon General, computer should not use list for membership testing because of the risk of being slow.

bookmarks: rewrite pushing bookmarks in "localrepository.push()" by "compare()" This patch adds "updateremote()", which uses "compare()" to compare bookmarks between the local and the remote repositories, to replace pushing local bookmarks in "localrepository.push()".

bookmarks: rewrite pushing local bookmarks in "commands.push()" by "compare()" This patch adds "pushtoremote()", which uses "compare()" to compare bookmarks between the local and the remote repositories, to replace pushing local bookmarks in "commands.push()".