patch 7.4.1604

Problem:    Although emoji characters are ambiguous width, best is to treat
            them as full width.
Solution:   Update the Unicode character tables. Add the 'emoji' options.
            (Yasuhiro Matsumoto)

runtime/optwin.vim

@@ -1254,6 +1254,8 @@ if has("multi_byte")
   endif
   call append("$", "ambiwidth\twidth of ambiguous width characters")
   call <SID>OptionG("ambw", &ambw)
+  call append("$", "emoji\temoji characters are full width")
+  call <SID>BinOptionG("emo", &emo)
 endif