[GREENFOOT-58] Can't quick add (shift click) an object without a default constructor

Should be handled in a better way \- probably by not creating any drag-image if constructor does not exist.

When shift-click-placing an object that has no default constructor:

java.lang.NoSuchMethodException: Paint.() at java.lang.Class.getConstructor0(Class.java:2647) at java.lang.Class.getConstructor(Class.java:1629) at greenfoot.gui.classbrowser.ClassView.createInstance (ClassView.java:457) at greenfoot.gui.classbrowser.role.GreenfootClassRole $1.actionPerformed(GreenfootClassRole.java:134) ...

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Issue metadata

• Issue type: Bug
• Priority: Low
• Fix versions: 2.0