Feature release 1.2.0

• Fix glitches in Chrome: When aborting a drag operation or dragging an element on itself, Chrome on Linux sometimes sends move as dropEffect instead of none. This lead to elements sometimes disappearing. Can be reproduced by dragging an element over itself and aborting with Esc key. (issue #14)
• Fix dnd-allowed-types in nested lists: When a drop was not allowed due to the wrong element type, the event was correctly propagated to the parent list. Nevertheless, the drop was still executed, because the drop handler didn't check the type again. (issue #16)
• New callbacks: The dnd-draggable directive now has a new dnd-dragstart callback besides the existing dnd-moved and dnd-copied. The dnd-list directive got the callbacks dnd-dragover and dnd-drag added, which are also able to abort a drop. (issue #11)
• dnd-horizontal-list: Lists can be marked as horizontal with this new attribute. The positioning algorithm then positions the placeholder left or right of other list items, instead of above or below. (issue #19)
• dnd-external-sources: This attribute allows drag and drop accross browser windows. See documentation for details. (issue #9)
• pointer-events: none no longer required: The dragover handler now traverses the DOM until it finds the list item node, therefore it's child elements no longer require the pointer-events: none style.