Better flip logic, visuals improvement, and also advanced level section
featuring Aaron's modifier tutorial

Merge pull request #80 from aschrab/multiple_parents
Revert "Better flip logic, visuals improvement, and also advanced level section"

This reverts commit 5aa831fc850f8af449ac6d11c7968286feb9fd88.
Merge branch 'master' into gh-pages
Merge remote-tracking branch 'origin/master'
Hover events on level icons to expose names Issue #81