Fixed issue with form values and the rotate button where updated values for piece height and width were set via the #value bucket and therefore would stay resident the next time calculate was submitted. Form now alters values in both the [form_state][values] and [form_state][input] portions prior to regenerating the form.
Roughed in custom lead/tail checkbox and fields.
Added calculation logic to process custom leads and tails.
Added logic to save custom leads and tails.
Lead and tail field generation broken out into single function shared between layer types.
Loading function complete. Calculations upon load debugged. Handling added for incomplete piece information.