Propagation of 'Etot' parameter

As discussed in !333 (merged), the update st->hNoiseEst->Etot_last = Etot; currently done in function updt_enc_common() can be done much earlier in the processing flow. Consequently, the propagation of the parameter Etot can be reduced.

This change would make the processing more logical and simplify/remove the updates currently proposed in !333 (merged).