DragDrop event handlers
Made rightclick context menu in EditSeries to add and delete series
Fixed #9
Pressing delete on a node in the treeview now deletes it #8
Pressing delete on a node in the treeview now deletes it #8
Pressing enter on a node in the treeview in EditSeries now plays the corresponding episode.
Play methods moved from MainWindow to SeriesManger
Fixed #8
Merge branch 'EditSeries'

Conflicts:
	WindowsFormsApplication1/Forms/EditSeries.cs
	WindowsFormsApplication1/Forms/MainWindow.cs
	WindowsFormsApplication1/Function/SeriesManager.cs
Merge branch 'EditSeries'

Conflicts:
	WindowsFormsApplication1/Forms/EditSeries.cs
	WindowsFormsApplication1/Forms/MainWindow.cs
	WindowsFormsApplication1/Function/SeriesManager.cs