Adding sticky and unicode flags

Closes #33

src/js/parser/javascript/grammar.peg

@@ -1,5 +1,5 @@
 grammar JavascriptRegexp
-  root <- ( ( "/" regexp "/" flags:[igm]* ) / regexp flags:""? ) <Root>
+  root <- ( ( "/" regexp "/" flags:[yigmu]* ) / regexp flags:""? ) <Root>
   regexp <- match:match alternates:( "|" match )* <Regexp>
   match <- (!repeat) parts:match_fragment* <Match>
   anchor <- ( "^" / "$" ) <Anchor>

src/js/parser/javascript/root.js

@@ -9,7 +9,9 @@ export default {
   flagLabels: {
     i: 'Ignore Case',
     g: 'Global',
-    m: 'Multiline'
+    m: 'Multiline',
+    y: 'Sticky',
+    u: 'Unicode'
   },
 
   // Renders the root into the currently set container.