Issue #61 fix by adding an instruction link (#176)

* added instruction link to each alternative download version headings from 2.3

* updated installation link for older versions

updated installation link for older versions and used documentation router to route to the corresponding documentation page

* added route to documentation index

In case of any mismatch (but won't happen)

* fix version mismatch and removed version hacks from documentation

app/assets/css/pages/_download.styl

@@ -141,6 +141,15 @@
         font-size: 0.9em
         margin: 10px 0 20px
 
+    .previousVersionHeading
+        float:left
+
+    .instructionLink
+        margin-left: 8px
+        font-size: 12px
+        margin-top: 1em
+        line-height: 58px;
+
     .cli, .ui
         margin: 50px auto
     .starter, .cli, .ui, .starter-projects, .example-projects, .seed-projects

app/views/download.scala.html

@@ -24,6 +24,11 @@
 }
 }
 
+@versionAtLeast(v1: String, v2: String) = @{
+  import math.Ordering.Implicits._
+  v1.split('.').toSeq >= v2.split('.').toSeq
+}
+
 @main(title, "download") {
 
   <header id="top">
@@ -105,9 +110,16 @@ <h3 id="older-versions">Previous releases</h3>
       <p class="changelogLink"><a href="@routes.Application.changelog()">Changelog</a></p>
 
       <table class="releases">
-      @releases.previous.groupBy(_.version.slice(0, 3)).toSeq.sortBy(_._1).reverse.map { group =>
+      @releases.previous.groupBy(_.version.split('.').take(2).mkString(".")).toSeq.sortBy(_._1).reverse.map { group =>
         <tbody class="version">
-          <tr><th colspan="3"><h4>@group._1</h4></th></tr>
+          <tr>
+            <th colspan="3">
+              <h4 class="previousVersionHeading">@group._1</h4>
+              @if(versionAtLeast(group._1, "1.2")) {
+                <a href="@controllers.documentation.ReverseRouter.page(None, group._1 + ".x", if(versionAtLeast(group._1, "2.0")) "Installing" else "install")" class="instructionLink"> Setup Instructions</a>
+              }
+            </th>
+          </tr>
           @group._2.map { release =>
             <tr class="release">
               @renderRelease("downloadPreviousLink", release)