Motif dialog on load existing motifs behavior needs update.

[king]

When you load an analysis that has saved motifs, say 3 of them, then it will load the 3 motifs into the motif editor, but when you go to add a 4th motif, you have to edit one of the existing motifs to get a 4th motif box to pop up. By default, I think the motif editor should have n+1 motif boxes available, when n is the number of existing motifs.

[diane]

[434] fixes this.