docs(guide/$location): fix broken example demo

The demo of the hash-bang vs html5-mode deep links was broken since the introduction
of a check for previously bootstrapped elements. See this commit: 3ee744c

We fix this problem by applying a null for the injector value of the element of the
at the root of the sub-app.
It also turns out that it was not necessary, and if fact broke the demo, to replace
the $document service for the sub-app.  This was because the $compile service calls
`$document.createElement()`, which doesn't exist on a `div`.
Finally, the bootstrap CSS was limiting the width of the ngAddress bar input box,
which made it difficult to see the changing URLs.

Author: petebacondarwin

docs/content/guide/dev_guide.services.$location.ngdoc

@@ -447,17 +447,19 @@ In this examples we use `<base href="/base/index.html" />`
 
   function initEnv(name) {
     var root = angular.element(document.getElementById(name + '-mode'));
+    // We must kill a link to the injector for this element otherwise angular will
+    // complain that it has been bootstrapped already.
+    root.data('$injector', null);
     angular.bootstrap(root, [function($compileProvider, $locationProvider, $provide){
       $locationProvider.html5Mode(true).hashPrefix('!');
 
       $provide.value('$browser', browsers[name]);
-      $provide.value('$document', root);
       $provide.value('$sniffer', {history: name == 'html5'});
 
       $compileProvider.directive('ngAddressBar', function() {
         return function(scope, elm, attrs) {
           var browser = browsers[attrs.browser],
-              input = angular.element('<input type="text">').val(browser.url()),
+              input = angular.element('<input type="text" style="width: 400px">').val(browser.url()),
               delay;
 
           input.on('keypress keyup keydown', function() {