DRY refactor & fix: Don't ask the controller to load twice the dropdown data, put it on the decorator and you will remove duplication... and bugs
DRY klass solving on news_tematicas_controller (not trivial because the module and the class have the same name)
Class solving extended to all the controller...
tematica_id not only is allowed... it's needed
Unhounding
Merge pull request #40 from Soluciones/fix-newsletter-creation

As I don't see a global renaming instead of newstematica_klass to be part of this PR, I'll merge this as is. A renaming should be done, but on its own PR.