Sill Plate Supporting Member Options (v9

The options when selecting sill plate materials as a supporting member were somewhat unrealistic, in that

the default selection was "timber" rather than lumber,
they included built-up materials even though there is no mechanism to select plies,
they did not include the regular lumber materials, which would be the most common sill plate.

This has been corrected and the program includes lumber as the default sill plate material, and places heavier materials at the end of the list.