Bugs fixed

Fixed slight inaccuracies when using virtual sites with pressure coupling

Virtual sites were reconstructed after the system was propagated, but before scaling due to pressure coupling. For virtual site types which are not a linear combination of other atoms, this is not completely correct. Since the scaling due to pressure coupling is very small in healthy simulations, the resulting inaccuracies are expected to have been extremely minor, and in most cases undetectable.

Issue 3866

Correct dVremain/dl when nstdhdl > nstcalcenergy

When nstcalcenergy was not a multiple of nstdhdl, incorrect dVremain/dl terms were written in the energy file. Note that all dH/dl output in both dhdl.xvg and the energy file, which is used by e.g. gmx bar, was correct.