Prepare extrafields into categories
Add information message for option into categories setup
Implement extrafields into category create
Category extrafields on categories: edit and view
Manage extrafields deletion on categories
Merge branch 'cat_extrafields' of https://github.com/aternatik/dolibarr
into aternatik-cat_extrafields

Conflicts:
	htdocs/install/mysql/migration/3.5.0-3.6.0.sql