Add new version of 'draw_init_gui_text_objects' method
Add new version of 'draw_init_gui_text_objects' method

The new version of this method preallocates the TextBox objects for:
- the plot titles
- the contribution of poles and zeros
- the results

We initialize them below the figure such that a subsequent call to
'draw_align_textboxes' adjusts the height of the figure to accomodate
the TextBoxes.
(We don't know the exact height of the text at this point, yet.)

StefanRickli/anp