[emacs-support] support use of fci-mode

We used to force whitespace-mode on for everything in the Swift project
so people see their 80-column violations.  I personally like
https://www.emacswiki.org/emacs/FillColumnIndicator better, so I changed
things such that I could reverse the decision made by .dir-locals.el:

  (add-hook 'prog-mode-hook (lambda () (fci-mode t) (whitespace-mode -1)))

Author: Dave Abrahams

.dir-locals.el

@@ -1,47 +1,43 @@
-;===--- .dir-locals.el ---------------------------------------------------===;
-;
-; This source file is part of the Swift.org open source project
-;
-; Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
-; Licensed under Apache License v2.0 with Runtime Library Exception
-;
-; See http://swift.org/LICENSE.txt for license information
-; See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
-;
-;===----------------------------------------------------------------------===;
 ;;; Directory Local Variables
 ;;; For more information see (info "(emacs) Directory Variables")
 
 ((nil
-  (tab-width . 2)
-  (fill-column . 80)
-  (eval let* ((x (dir-locals-find-file default-directory))
-              (this-directory (if (listp x) (car x)
-                                (file-name-directory x))))
+  (eval let*
+        ((x (dir-locals-find-file default-directory))
+         (this-directory (if (listp x) (car x) (file-name-directory x))))
         (unless (featurep 'swift-project-settings)
-          (add-to-list 'load-path  (concat this-directory "utils") :append)
+          (add-to-list 'load-path
+                       (concat this-directory "utils")
+                       :append)
           (let ((swift-project-directory this-directory))
-          (require 'swift-project-settings)))
-        (set (make-local-variable 'swift-project-directory) this-directory))
-  (c-file-style . "swift")
-  )
+            (require 'swift-project-settings)))
+        (set (make-local-variable 'swift-project-directory)
+         this-directory)
+        )
+  (tab-width . 2)
+  (fill-column . 80)
+  (c-file-style . "swift"))
  (c++-mode
-  (whitespace-style . (face lines indentation:space))
-  (eval . (whitespace-mode)))
- (objc-mode
-  (whitespace-style . (face lines indentation:space))
-  (eval . (whitespace-mode)))
+  (whitespace-style face lines indentation:space))
  (c-mode
-  (whitespace-style . (face lines indentation:space))
-  (eval . (whitespace-mode)))
+  (whitespace-style face lines indentation:space))
+ (objc-mode
+  (whitespace-style face lines indentation:space))
+ (prog-mode
+  (eval add-hook 'prog-mode-hook
+        (lambda nil
+          (whitespace-mode 1))
+        (not :APPEND)
+        :BUFFER-LOCAL))
  (swift-mode
   (swift-find-executable-fn . swift-project-executable-find)
   (swift-syntax-check-fn . swift-project-swift-syntax-check)
-  (whitespace-style . (face lines indentation:space))
-  (eval . (whitespace-mode))
+  (whitespace-style face lines indentation:space)
   (swift-basic-offset . 2)
   (tab-always-indent . t)))
 
+
+
 ;; Local Variables:
 ;; eval: (whitespace-mode -1)
 ;; End: