Create alert initial files
make it closeable for ajax errors
Complement last commit
Create proper error messages using alert and angular directives
Show validation message before publishing
Pass the chapter id to the validation data

I made this change for consistency, but I can't actually use the data to
scroll to the chapter after it is validated, because the angular smooth
scroll module does not watch the properties through their directive:
https://github.com/d-oliveros/angular-smooth-scroll/issues/16
There is no need to clear scroll or focus