added method question.survey() (return suvey of a question)
added relationship between section and survey (to access "root")
added hybrid_property in question
unfinished matching (only missing part of the third part prize)
delete seed
pruebas...
finished duplicate_sections
fixed add/edit question render(before disable question type)
update decorators (now check with root instead of parent)
update from_xml, to_xml
updated javascript to selection in decision
modified validate (forms researcher)
fixed check/render
update survey!
update tareas & implementaciones