Make new layer alignment setting available

[stfnp]

The new solver has an input that defines which point of the cross sections is aligned with the profile curve. Previously the profile curve was always fixed at the back of the bow. This setting is however not yet accessible to users in Version 0.10.

Implementation:

• Add alignment setting to tree item "Layers"
• When selected, show a 2d plot of the complete layer stack where the x-axis is basically the profile. That way the alignment setting becomes more intuitive. (Related: #241)