[IMP] website_mail: make the template / mail editor work. We now have a limited

[IMP] website_mail: make the template / mail editor work. We now have a limited
set of fields that we try to edit (body_html and body for body, email_from and email for
email-from, name and subject for subject), because t-field is not dynamic. If the model
that should be edited does not hold those fields, the mail editor won't work.

Also fixed editor not being actiated when going into the body edition.

bzr revid: tde@openerp.com-20140416105901-vavkh9erjsq4mof9