Fixed uninitialized dummy* variables.

This fixes issue #113.

Fixed uninitialized dummy* variables.  I tested this by running the code for the "pnw" test cells, for the following cases:
1. 24hwb, OUTPUT_FORCE=FALSE
2. 1heb, OUTPUT_FORCE=TRUE
I verified that the results were exactly the same as for VIC.4.1.2.k.

I also ran valgrind -v --leak-check=full and confirmed no errors resulting from this change.  However, I did find a memory leak in read_soilparam.c.  I will fix this next.