BUG: refs #912. Remove "upload a directory" mode link

The underlying functionality is kept, but there have been several reports
of bugs related to the html5 directory uploader, so I've hidden the
link to use it until we can straighten them out.

Author: zachmullen

core/views/upload/simpleupload.phtml

@@ -62,11 +62,6 @@ PURPOSE.  See the above copyright notices for more information.
                 <div class="file_upload_label"><?php echo $this->t('Browse or drop files')?></div>
                 <div class="file_upload_label_folder"><?php echo $this->t('Browse')?></div>
             </form>
-            <div id="changeUploadMode" style="display:none;">
-              <br/>
-              <?php echo $this->t('or')?> <a style="color:blue; cursor:pointer;" class="uploadModeLink" id="uploadModeFolderLink"><?php echo $this->t('upload a folder')?></a>
-              <a style="color:#56758B; cursor:pointer;" class="uploadModeLink" id="uploadModeFileLink"><?php echo $this->t('upload files')?></a>
-            </div>
 
             <div class="uploadedFilesWrapper">
               <table class="files">