Moved placeholder logic out of Javascript and the DOM

and into CSS
Removed cnxmlplus handler
Moved title out of the type-container element
type-container is removed from the serialized DOM
Merge branch 'master' into placeholder-in-css
Renamed variable
Notes with textnode children will get a para
fix typo in semanticBlock makeClean
fix images and exercises
add note type if it doesn't exist
fix bug in note title handling
Merge branch 'master' into placeholder-in-css
fix type selection for notes
remove unused variable in note plugin
Merge pull request #6 from oerpub/placeholder-in-css

Moved placeholder logic out of Javascript and the DOM and into CSS