bookmarks: parse out --inactive to action early The --inactive option can't be directly mapped to an action or a modifier. With any names, it means to add/rename to inactive bookmarks. Without names, it means to deactivate the current bookmark. This patch separates them to "inactive" flag and "action == 'inactive'".

bookmarks: parse out implicit "add" action early This prepares for adding -l/--list option, which can be combined with the positional arguments.

bookmarks: clarify that opts['rename'] points to an old bookmark to be renamed

bookmarks: refactor option checking to pick one from --delete/rename/active