Exception thrown when dragging elements

[benabbon]

When we click & move a picture for example in the editor, and the picture outstrips the application limits, it throws an exception :

Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: Too small byte buffer size 0x0 [0] > 0.
at com.sun.glass.ui.Pixels.(Pixels.java:91)

I think we need to forbid the drag & move for all objects except when we need it (for instance : tooltips).

[twitwi]

I don't get the exception with version 0.3 on Linux 64, jdk8u20 (but maybe logs are hidden) but I can move the tooltips and cursor.