New 'delete' command for deleting a resource loaded inside an editor (todo: factorize part of it with 'save' command); renaming of 'data-validation' parameter into 'data-validation-output' parameter; improved demonstration editor aligned with AXEL's one; bug corrections; fresh axel-forms.js prebuilt library.
Merge branch 'master' into gh-pages

Conflicts:
	editor/editor.xhtml