revset: rename variable to avoid shadowing with builtin next() function https://docs.python.org/2/library/functions.html#next

histedit: add experimental config for using the first word of the commit This allows users to start a commit with "verb! ..." so that when this is opened in histedit, the default action will be "verb". For example, "roll! foo" will default to the action "roll". Currently, we'll allow any known verb to be used but this is experimental.

histedit: add optional parameter for determining intial editor line A simple refactor to allow us to change the default verb for the initial editor display.