unrar: complete on *.exe (#337)

To support some common rar self-extracting (SFX) archives.

Author: andreabravetti

completions/unrar

@@ -13,7 +13,7 @@ _unrar()
         if [[ $cword -eq 1 ]]; then
             COMPREPLY=( $(compgen -W 'e l lb lt p t v vb vt x' -- "$cur") )
         else
-            _filedir rar
+            _filedir '@(rar|exe)'
         fi
     fi