Support all nu/rnu permutations

Closes #41.
Fix typo

Closes #42.
Fix count support for ]a

Closes #43.
Merge branch 'master' of git://github.com/tpope/vim-unimpaired

* 'master' of git://github.com/tpope/vim-unimpaired:
  Fix count support for ]a
  Fix typo
  Support all nu/rnu permutations

Conflicts:
	plugin/unimpaired.vim