Fix bug, firebolt can't find at beginning or end of line
Fix bug with repeat when seek switches from motion to operator

- Add repeat callback functions to control update of 'inclusive'
  variable
Change seek operator mappings from "s" to "z"

- Mappings are taken by surround.vim
- Idea taken from sneak.vim, I'm not sure if this is optimal or if I
  even like it, but I don't think there's a better option. we'll see how
  this goes.  ; and , still work.