Restore original options editor on core init (#423)

* Restore original options editor on core init

When initializing core, as a workaround, options.editor is.
temporarily set to null for copying purposes, but does not.
set it back. This results in unexpected modification of the.
passed param and also makes the editor null for subsequent.
usages. Restored the parameter's editor back after copy.

* Correct a use case for null options

* Code formatting to include braces

Author: GoGoCarl

src/js/core.js

@@ -51,6 +51,9 @@
         }
         this.options = $.extend(true, {}, defaults, options);
         this.options.editor = editor;
+        if (options) {
+            options.editor = editor; // Restore original object definition
+        }
 
         this._defaults = defaults;
         this._name = pluginName;