Added more (extract, form.choose, + more specific)

Added more methods etc/fleshed out the library a bit more.

Currently changing the $M.form object to a method instead (e.g.
$M.form(form_attribute) ) returning $M so that method chaining is
possible.

That is, it would be something like

$M.form("ID:form_1").choose("ID:sel_year", "name", "2013")

rather than

$M.form.choose("ID:form_1","ID:sel_year", "name", "2013")