StructureChange

1. Add reminder of nonstationary vars to nlma_th_moments
2. Dynare's oo_ array is no longer a global
3. full_block_dr_new.m is removed from pruning_abounds.m. When unfolding
is required (order = 3 and pruning = 0), it will be done in the four
main functions, not by pruning_abounds.m itself.