Fix typo in Intra_R_Add_Exocyclic
Allow *3 to be Cdd in the DoubleBond group as well in Intra_R_Add_Exocyclic

The top level groups all allow Cdd atom type as *3, but we would not
descend the tree to get any decent data, because the double bond group was
defined as Cd only. Now at least we will get to a level two node, although
we have no relevant data below this.
Strip whitespace at end of lines
Forbid triple bonds in 3- and 4-membered rings.

We don't have meaningful ring corrections for these, so they end up being
*far* too stable if allowed.
Until QM thermo, or better ring corrections, become the norm, I think it's probably best
to forbid these structures.