chore(docs): regroup version selector options into major branches and latest

Before this change we grouped by the  discontinued stable/unstable distinction.

Closes #10053

Author: thorn0

docs/app/src/versions.js

@@ -1,7 +1,10 @@
+"use strict";
+
 angular.module('versions', [])
 
 .controller('DocsVersionsCtrl', ['$scope', '$location', '$window', 'NG_VERSIONS', function($scope, $location, $window, NG_VERSIONS) {
   $scope.docs_version  = NG_VERSIONS[0];
+  $scope.docs_versions = NG_VERSIONS;
 
   for(var i=0, minor = NaN; i < NG_VERSIONS.length; i++) {
     var version = NG_VERSIONS[i];
@@ -13,9 +16,8 @@ angular.module('versions', [])
     minor = version.minor;
   }
 
-  $scope.docs_versions = NG_VERSIONS;
   $scope.getGroupName = function(v) {
-    return v.isLatest ? 'Latest' : (v.isStable ? 'Stable' : 'Unstable');
+    return v.isLatest ? 'Latest' : ('v' + v.major + '.' + v.minor + '.x');
   };
 
   $scope.jumpToDocsVersion = function(version) {

lib/versions/version-info.js

@@ -91,15 +91,6 @@ var getTaggedVersion = function() {
   return null;
 };
 
-/**
- * Stable versions have an even minor version and have no prerelease
- * @param  {SemVer}  version The version to test
- * @return {Boolean}         True if the version is stable
- */
-var isStable = function(version) {
-  return semver.satisfies(version, '1.0 || 1.2') && version.prerelease.length === 0;
-};
-
 /**
  * Get a collection of all the previous versions sorted by semantic version
  * @return {Array.<SemVer>} The collection of previous versions
@@ -119,8 +110,6 @@ var getPreviousVersions =  function() {
       })
       .filter()
       .map(function(version) {
-        version.isStable = isStable(version);
-
         version.docsUrl = 'http://code.angularjs.org/' + version.version + '/docs';
         // Versions before 1.0.2 had a different docs folder name
         if ( version.major < 1 || (version.major === 1 && version.minor === 0 && version.dot < 2 ) ) {