add reply={url} query param for posting a note

Support reply bookmarklets, and hopefully the Firefox Social API
"Share" provider too.

controllers/controllers.php

@@ -43,9 +43,14 @@ function generate_login_token() {
 
 $app->get('/new', function() use($app) {
   if($user=require_login($app)) {
+    $params = $app->request()->params();
 
     $entry = false;
     $photo_url = false;
+    $in_reply_to = '';
+
+    if(array_key_exists('reply', $params))
+       $in_reply_to = $params['reply'];
 
     $test_response = '';
     if($user->last_micropub_response) {
@@ -60,6 +65,7 @@ $app->get('/new', function() use($app) {
 
     $html = render('new-post', array(
       'title' => 'New Post',
+      'in_reply_to' => $in_reply_to,
       'micropub_endpoint' => $user->micropub_endpoint,
       'micropub_scope' => $user->micropub_scope,
       'micropub_access_token' => $user->micropub_access_token,

views/new-post.php

@@ -10,7 +10,7 @@
 
         <div class="form-group">
           <label for="note_in_reply_to"><code>in-reply-to</code> (optional, a URL you are replying to)</label>
-          <input type="text" id="note_in_reply_to" value="" class="form-control">
+          <input type="text" id="note_in_reply_to" value="<?= $this->in_reply_to ?>" class="form-control">
         </div>
 
         <div class="form-group">