Vim: Ignore .*.s[a-w][a-z] and .s[a-w][a-z] swap files

.*.s[a-w][a-z] matches named swap files.
.s[a-w][a-z] matches unnamed swap files.

Global/vim.gitignore

 *.s[a-w][a-z]
+.s[a-w][a-z]
 *.un~
 Session.vim
 .netrwhist