JI-5682 cropper UI (#197)

* JI-5683 replace darkroom with cropper

* JI-5683 set new image for existing cropper instance

* JI-5682 add other handles and some UI

* JI-5682 hide handles on move/resize selector

* JI-5682 add selector masks

* JI-5682 move html inside cropper library

* JI-5682 add optional initial positioning and sizing options for selector

* JI-5682 update initialize function

* JI-5682 add buttons first draft

* JI-5682 finish cropper UI integration

* JI-5682 add comments

* JI-5682 remove unused lines

* JI-5682 update variable names

* JI-5682 replace onPointerUp functions with singularentity

* JI-5682 improve readability of updateMask

* JI-5682 reuse variables within crop function

* JI-5682 replace console.log with warning

* JI-5682 add empty lines

* JI-5682 update image loaded handling

* JI-5682 resize cropper on window resize

* JI-5682 add keyup event handlers and accessibility attributes

* JI-5682 improve cropper responsiveness

* JI-5682 update tooltip custom css class

* JI-5682 update custom cropper tooltip class

Author: devland

h5peditor.class.php

@@ -9,7 +9,7 @@ class H5peditor {
   );
 
   public static $styles = array(
-    'libs/darkroom.css',
+    'libs/cropper.css',
     'styles/css/h5p-hub-client.css',
     'styles/css/fonts.css',
     'styles/css/application.css',