lem.el update 0.20

added lots of stuff in this update, some of which may be a little green still.

• commands to navigate comment trees
  • up to top-level comment
  • prev/next same-level comment
• various commands to selectively fold (hide) comment branches
  • un/fold current comment
  • un/fold current comment + its children
  • un/fold current comment’s entire branch
  • un/fold entire buffer
• added more sorting/listing drop-down widgets to make it easier to see what sorting is in effect (and to change sorting by mouse)
• fix tab navigation to (hopefully) all links everywhere
• make default sorting/listing in views better match the web UI
• fix sorting options in user view
• various other fixes

one thing to note is that this release switches the S/s bindings, for consistency.