Changed the click and drag bindings to check whether the initial press
came from a double-1 binding to move the editor cursor. If so drag the
cursor, otherwise do the old plot-drag code.


git-svn-id: svn://svn.code.sf.net/p/staden/code/staden/trunk@3562 ba6f2710-ca9f-427c-89d3-5bf716dbc8e1