vim-patch:7.4.1673 (#5141)

Problem:    The justify plugin has to be copied or sourced to be used.
Solution:   Turn it into a package.

2946d0236d

Justification for changes that do not carry over

- `Filelist` does not exist in neovim
- neovim does not have a `README.txt` in `runtime/macros`

src/nvim/version.c

@@ -604,7 +604,7 @@ static int included_patches[] = {
   1676,
   1675,
   // 1674 NA
-  // 1673,
+  1673,
   // 1672 NA
   // 1671,
   // 1670,