Added Sortable component stub.

Refactored to move generic behavior of Draggable and Droppable to a parent class

Refactorig of Sortable to share code with Draggable and Droppable using the same abstract classes
Added sortable zones.
Name refactoring
Added drop on parent element when the list is empty
Changed default Drag&Drop behaviour: now it is mandatory to declare a drop zone, otherwise, by default, the dragged object cannot be dropped
Added first unit test for sortable
Added sortable tests
Removed need for nodeId in the sortable service
A light in the dark... Complete refactoring of the Drag&Drop and Sortable code. A change in the code structure permitted to greatly simplify the code.
The Sortable component works almost fine in dart but still behaves wrongly in when compiled to js (tested in FF, Chrome and Opera).
Commented failing tests
Ignoring eclipse settings folder
fixed wrong css classes in firefox
Code refactoring
Fixed wrong behaviour in Firefox
Start Upgrade to angular 1.0
Fixed dragDrop demos
Fixed sortable demos
Merge remote-tracking branch 'origin' into dragdrop

Conflicts:
	.gitignore
	pubspec.yaml
	test/ui_tests.dart
	web/main.dart
moving tests to guiness
Merge remote-tracking branch 'origin' into dragdrop

Conflicts:
	pubspec.yaml
	web/main.dart