Improve drop zones and feel of dragging in file tree

services/web/public/coffee/ide/file-tree/controllers/FileTreeRootFolderController.coffee

@@ -11,4 +11,6 @@ define [
 			for dropped_entity in entities
 				ide.fileTreeManager.moveEntity(dropped_entity, rootFolder)
 			$scope.$digest()
+			# clear highlight explicitly
+			$('.file-tree-inner .droppable-hover').removeClass('droppable-hover')
 	]

services/web/public/coffee/ide/file-tree/directives/draggable.coffee

@@ -9,7 +9,6 @@ define [
 						element.draggable
 							delay: 250
 							opacity: 0.7
-							helper: "clone"
 							scroll: true
 							helper: scope.$eval(attrs.draggableHelper)
 		}

services/web/public/coffee/ide/file-tree/directives/droppable.coffee

@@ -9,6 +9,7 @@ define [
 						element.droppable
 							greedy: true
 							hoverClass: "droppable-hover"
+							tolerance: "pointer"
 							accept: attrs.accept
 							drop: scope.$eval(attrs.onDropCallback)
 		}

services/web/public/stylesheets/app/editor/file-tree.less

@@ -24,6 +24,8 @@ aside#file-tree {
 		font-size: 0.8rem;
 		margin: 0;
 		padding: (@line-height-computed / 4) 0;
+		overflow-x: hidden;
+		height: 100%;
 
 		ul {
 			margin-left: (@line-height-computed / 2);
@@ -46,7 +48,7 @@ aside#file-tree {
 					line-height: 1.6;
 				}
 				&.droppable-hover {
-					background-color: @file-tree-droppable-background-color;
+					background-color: fade(@file-tree-droppable-background-color, 60%);
 				}
 			}
 
@@ -121,7 +123,7 @@ aside#file-tree {
 	}
 
 	ul.droppable-hover {
-		background-color: @file-tree-droppable-background-color;
+		background-color: fade(@file-tree-droppable-background-color, 60%);
 	}
 }