Fails to handle numbers

[genelkim]

(ulf2english:ulf2english '((SUB HOW.PQ ((PRES DO.AUX-S) YOU.PRO ((SAY.V (|"| 2 |"|)) (ADV-A (IN.P | Latin|)) *H))) ?))
Error: Can't coerce 2 to type LIST.

[genelkim]

Added test to check this failure doesn't happen again in this commit.

The major problem from this issue is fixed by a commit in ulf-lib.

I will add a separate issue for the fact that the result from ulf2english function isn't what we actually want.