Merge branch 'master' into ecb-master

.travis.yml

src/@dseries/lineartrend.m

src/@dseries/onesidedhpcycle.m

src/@dseries/onesidedhpcycle_.m

src/@dseries/onesidedhptrend.m

src/@dseries/onesidedhptrend_.m

src/@dseries/subsref.m

src/initialize_dseries_toolbox.m

...ilities/missing/one_sided_hp_filter/one_sided_hp_filter.m