Revised model for ffd implementation.

Revised conditional classes.\nChanged windowHasShade to haveShade to ensure consistent use across library.
Corrected wrong size of connector.
Made TSha a conditional connector.
Moved conditional connector statement.
Removed condition on connector.

This is done to ensure consistency with the use of this connector in other models.
Removed condition on connector.

This is done to ensure consistency with the use of this connector in other models.
Removed assignment of value to input connector.

This should be done from the outside.
Corrected wrong sign of input signal.