Fixed some bugs that appeared after merge

regtest/pamm/rt-pamm-aperiodic/deriv.reference

src/multicolvar/MultiColvarBase.cpp

src/multicolvar/MultiColvarBase.h

src/multicolvar/MultiColvarFunction.cpp

src/multicolvar/MultiColvarFunction.h

src/pamm/HBPammMatrix.cpp

src/pamm/PAMM.cpp

src/vesselbase/Moments.cpp