started remodelling the functionality of subplots. _subplot_xy() will take a rect-list as position and create new Axes object at this exact location. _subplot_timeinterval, _subplot_askwhere and plot_timeinterval use this.
added new subplot functionality to scalp plots.
more save_format switches
added function for grid calculation.
refactored plot_tenten() for new subplotting usage. code cleanup.