This fixes #704.

(manually cherry picked from commit 0f28422e9fdb4281e565bdf0f7edd3e2b1677652)

Conflicts:
	matlab/@dseries/minus.m
	matlab/@dseries/mpower.m
	matlab/@dseries/mrdivide.m
	matlab/@dseries/mtimes.m
	matlab/@dseries/plus.m