flushLegend makes the legend border flush with the lines of the plot axis. The legend location/position can be made flush with any corner, or at the centre-point of the sides. The location/position is assigned using standard Matlab legend notation (i.e. position_string = 'north', 'south', 'east', 'west', 'northeast', 'northwest' etc.) and abbreviations of these (i.e. position_string = 'n','s', 'e','w','ne','nw', etc).
Making the legend flush with the axis can be useful for making plots looking cleaner, especially if there is limited available space in the plot due to multiple data lines.

Usage:
Minimal usage: flushLegend( legend_handle )
Optional axis handle: flushLegend( legend_handle, axis_handle )
Optional position string: flushLegend( legend_handle, position_string )
Optional BOTH: flushLegend( legend_handle, axis_handle, positionString ): e.g. flushLegend( legend_handle, axis_handle, 'northeast' )