update comment
check against an empty string, too
allow a custom url to be set on each directive
build
update demo
bump version to 0.0.9
Merge branch 'hotfix/0.0.9'

* hotfix/0.0.9:
  bump version to 0.0.9
  update demo
  build
  allow a custom url to be set on each directive
  check against an empty string, too
  update comment
Merge branch 'master' into gh-pages

* master:
  bump version to 0.0.9
  update demo
  build
  allow a custom url to be set on each directive
  check against an empty string, too
  update comment