Allow to use functions for maskobj_name/masksky_name

Status Job ID Name Coverage
  Test
passed #8344
check-setup

00:02:06

passed #8345
docs

00:05:14

passed #8341
py35

00:06:10

76.0%
passed #8342
py36

00:06:31

76.0%
passed #8343
py37

00:15:27

77.0%