Add cssom-view.vim

This support based on latest working draft, not dev edition. The dev
edition has removed `instant` value, but it is not a big problem.

See also: http://www.w3.org/TR/2013/WD-cssom-view-20131217/

This resolves #33.

after/syntax/css/cssom-view.vim

@@ -0,0 +1,2 @@
+syn match cssFontProp contained "\<scroll-behavior\>"
+syn keyword cssFontAttr contained instant smooth

after/syntax/html.vim

@@ -48,4 +48,5 @@ syn include @htmlCss syntax/css/css-values.vim
 syn include @htmlCss syntax/css/css-variables.vim
 syn include @htmlCss syntax/css/css-will-change-1.vim
 syn include @htmlCss syntax/css/css-writing-modes-3.vim
+syn include @htmlCss syntax/css/cssom-view.vim
 syn include @htmlCss syntax/css/selectors4.vim

test/test.css

@@ -161,6 +161,11 @@
   display: ethiopic-numeric;
 }
 
+.cssom-view {
+  scroll-behavior: instant;
+  display: smooth;
+}
+
 .display {
   box-suppress: flow;
   display: flow-root;

test/test.html

@@ -184,6 +184,12 @@
 }
 </style>
 <style>
+.cssom-view {
+  scroll-behavior: instant;
+  display: smooth;
+}
+</style>
+<style>
 .display {
   box-suppress: flow;
   display: flow-root;