tests/test-rebuildstate.t

dispatch: offer near-edit-distance suggestions for {file,rev}set functions

Before this patch, when I have a brain fart and type `hg log -r
'add(foo)'`, hg exits and just says add isn't a function, leading me
to the help page for revset to figure out how to spell the
function. With this patch, it suggests 'adds' as a function I might
have meant.

basic test for hg debugrebuildstate

  $ hg init repo
  $ cd repo

  $ touch foo bar
  $ hg ci -Am 'add foo bar'
  adding bar
  adding foo

  $ touch baz
  $ hg add baz
  $ hg rm bar

  $ hg debugrebuildstate

state dump after

  $ hg debugstate --nodates | sort
  n 644         -1 set                 bar
  n 644         -1 set                 foo

status

  $ hg st -A
  ! bar
  ? baz
  C foo

  $ cd ..