Update runtime files.

Includes changing &sw to shiftwidth() for all indent scripts.
diff --git a/runtime/indent/ruby.vim b/runtime/indent/ruby.vim
index a97f482..d8733db 100644
--- a/runtime/indent/ruby.vim
+++ b/runtime/indent/ruby.vim
@@ -404,11 +404,7 @@
   " ----------
 
   " The value of a single shift-width
-  if exists('*shiftwidth')
-    let sw = shiftwidth()
-  else
-    let sw = &sw
-  endif
+  let sw = shiftwidth()
 
   " For the current line, use the first argument if given, else v:lnum
   let clnum = a:0 ? a:1 : v:lnum