update COPYING

It includes the new FSF office address.

Reported-by: Kevin Fenzi <kevin@scrye.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
set: xml: data_type/data_len are optional

Don't print data_type and data_len if they aren't set.
Also, they are optional when parsing.

Printing and parsing unconditionally leads to false values and other errors.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>