* VSP efficiency + retrieving efficiency directly
Changes to the getenergy function (in hydraulic.c) to compute the
correct efficiency of variable speed pumps according to the affinity
laws.
Changes to epanet2.h and epanet.c are for retrieving the efficiency of
pumps throught the ENgetlinkvalue function (code 16 for efficiency)
* Update epanet.c
* VSP efficiency (incl. bas and vb file)
- bas and vb file have been updated with code 16 for efficiency.
- Retrieving efficiency case has been improved.
