chore(docs): add docs versioning

Fixes #3670
Closes #4646

Author: Foxandxss

Diff for: Gruntfile.js

@@ -353,7 +353,7 @@ module.exports = function(grunt) {
     grunt.config('concat.dist_tpls.src', grunt.config('concat.dist_tpls.src')
                  .concat(srcFiles).concat(tpljsFiles));
 
-    grunt.task.run(['concat', 'uglify', 'makeModuleMappingFile', 'makeRawFilesJs']);
+    grunt.task.run(['concat', 'uglify', 'makeModuleMappingFile', 'makeRawFilesJs', 'makeVersionsMappingFile']);
   });
 
   grunt.registerTask('test', 'Run tests on singleRun karma server', function () {
@@ -392,6 +392,33 @@ module.exports = function(grunt) {
                   grunt.config('meta.banner'), grunt.config('meta.cssFileBanner'));
   });
 
+  grunt.registerTask('makeVersionsMappingFile', function () {
+    var done = this.async();
+
+    var exec = require('child_process').exec;
+
+    var versionsMappingFile = 'dist/versions-mapping.json';
+
+    exec('git tag --sort -version:refname', function(error, stdout, stderr) {
+      // Let's remove the oldest 14 versions.
+      var versions = stdout.split('\n').slice(0, -14);
+      var jsContent = versions.map(function(version) {
+        return {
+          version: version,
+          url: '/bootstrap/versioned-docs/' + version
+        };
+      });
+      jsContent[0] = {
+        version: 'Current',
+        url: '/bootstrap'
+      };
+      grunt.file.write(versionsMappingFile, JSON.stringify(jsContent));
+      grunt.log.writeln('File ' + versionsMappingFile.cyan + ' created.');
+      done();
+    });
+
+  });
+
   /**
    * Logic from AngularJS
    * https://github.com/angular/angular.js/blob/36831eccd1da37c089f2141a2c073a6db69f3e1d/lib/grunt/utils.js#L121-L145

Diff for: misc/demo/assets/app.js

@@ -47,6 +47,12 @@ angular.module('ui.bootstrap.demo', ['ui.bootstrap', 'plunker', 'ngTouch', 'ngAn
 .controller('DownloadCtrl', DownloadCtrl);
 
 function MainCtrl($scope, $http, $document, $uibModal, orderByFilter) {
+  // Grab old version docs
+  $http.get('/versions-mapping.json')
+    .then(function(result) {
+      $scope.oldDocs = result.data;
+    });
+
   $scope.showBuildModal = function() {
     var modalInstance = $uibModal.open({
       templateUrl: 'buildModal.html',

Diff for: misc/demo/index.html

@@ -50,6 +50,16 @@
                     </ul>
                 </li>
                 <li><a href="#getting_started">Getting started</a></li>
+                <li class="dropdown" uib-dropdown>
+                    <a role="button" class="dropdown-toggle" uib-dropdown-toggle>
+                        Previous docs <b class="caret"></b>
+                    </a>
+                    <ul class="dropdown-menu">
+                        <li ng-repeat="version in oldDocs">
+                            <a ng-href="{{version.url}}">{{version.version}}</a>
+                        </li>
+                    </ul>
+                </li>
             </ul>
         </nav>
         <nav class="visible-xs" uib-collapse="!isCollapsed">