are sleep modes part of the core in the meantime ?

in the past you have to deal heavily with registers to enable the deep sleep mode on the SAMD21 while still wanting to "listen" to pin interrupts, see for example here --> or here -->

on gitub @sandeepmistry wrote on June'16 "We'll need to figure out a plan to incorporate low power into the core ..."

are there any new core functions regarding the sleep modes of the SAMD21 or is there some kind of "low-power library" available for that ?