Update runtime files.

Includes changing &sw to shiftwidth() for all indent scripts.
diff --git a/runtime/indent/yaml.vim b/runtime/indent/yaml.vim
index 3201462..3eb16f8 100644
--- a/runtime/indent/yaml.vim
+++ b/runtime/indent/yaml.vim
@@ -1,7 +1,7 @@
 " Vim indent file
 " Language:         YAML
 " Maintainer:       Nikolai Pavlov <zyx.vim@gmail.com>
-" Last Change:	    2015 Nov 01
+" Last Change:	    2017 Jun 13
 
 " Only load this indent file when no other was loaded.
 if exists('b:did_indent')
@@ -24,14 +24,6 @@
     finish
 endif
 
-if exists('*shiftwidth')
-    let s:shiftwidth = function('shiftwidth')
-else
-    function s:shiftwidth()
-        return &shiftwidth
-    endfunction
-endif
-
 function s:FindPrevLessIndentedLine(lnum, ...)
     let prevlnum = prevnonblank(a:lnum-1)
     let curindent = a:0 ? a:1 : indent(a:lnum)
@@ -119,7 +111,7 @@
         "
         " - |-
         "     Block scalar without indentation indicator
-        return previndent+s:shiftwidth()
+        return previndent+shiftwidth()
     elseif prevline =~# '\v[:-]\ [|>]%(\d+[+\-]?|[+\-]?\d+)%(\#.*|\s*)$'
         " - |+2
         "   block scalar with indentation indicator
@@ -155,7 +147,7 @@
                 \                             '\v)%(\s+|\s*%(\#.*)?$))*'
         " Mapping with: value
         "     that is multiline scalar
-        return previndent+s:shiftwidth()
+        return previndent+shiftwidth()
     endif
     return previndent
 endfunction