Add missing translations to en.json

Also add `Search` to translatable strings

en.json

@@ -14,6 +14,7 @@
     "general.forParents": "For Parents",
     "general.forEducators": "For Educators",
     "general.guidelines": "Community Guidelines",
+    "general.help": "Help",
     "general.jobs": "Jobs",
     "general.joinScratch": "Join Scratch",
     "general.legal": "Legal",
@@ -27,11 +28,13 @@
     "general.scratchEd": "ScratchEd",
     "general.scratchFoundation": "Scratch Foundation",
     "general.scratchJr": "ScratchJr",
+    "general.search": "Search",
     "general.signIn": "Sign in",
     "general.statistics": "Statistics",
     "general.support": "Support",
     "general.termsOfUse": "Terms of Use",
     "general.username": "Username",
+    "general.viewAll": "View All",
     "general.whatsHappening": "What's Happening?",
     "general.wiki": "Scratch Wiki",
     "footer.about": "About Scratch",    
@@ -47,6 +50,7 @@
     "intro.tryItOut": "TRY IT OUT",
     "login.forgotPassword": "Forgot Password?",
     "navigation.signOut": "Sign out",
+    "news.scratchNews": "Scratch News",
     "parents.FaqAgeRangeA": "While Scratch is primarily designed for 8 to 16 year olds, it is also used by people of all ages, including younger children with their parents.",
     "parents.FaqAgeRangeQ": "What is the age range for Scratch?",
     "parents.FaqResourcesQ": "What resources are available for learning Scratch?",

src/components/navigation/navigation.jsx

@@ -28,6 +28,10 @@ var defaultMessages = defineMessages({
     myStuff: {
         id: 'general.myStuff',
         defaultMessage: 'My Stuff'
+    },
+    search: {
+        id: 'general.search',
+        defaultMessage: 'Search'
     }
 });
 
@@ -222,7 +226,7 @@ var Navigation = React.createClass({
                     <li className="search">
                         <form action="/search/google_results" method="get">
                             <Input type="submit" value="" />
-                            <Input type="text" placeholder="Search" name="q" />
+                            <Input type="text" placeholder={formatMessage(defaultMessages.search)} name="q" />
                             <Input type="hidden" name="date" value="anytime" />
                             <Input type="hidden" name="sort_by" value="datetime_shared" />
                         </form>