Issue51 bestest

Updating all BESTEST Cases #51 based on the Annex 60 implementation and resulting changes in IDEAS Interfaces.
 - Solves the n50-propagation in the zone
 - Adds runable model for each case separately
 - BESTEST results give a remarkable overestimating of QHea in Case 640 and underestimation of QCoo in Case 650, while their heavyweight alternatives in Case 940 and 950 check perfectly within range.
 - BESTEST results generally give a slight underestimation of the peak heatign and cooling loads, defined by the temperature-dependent indoor convective surface coefficients.