Create rules for each member of a list

Create rules for each member of a list

This patch extends the NWFilter driver for Linux (ebiptables) to create
rules for each member of a previously introduced list. If for example
an attribute value (internally) looks like this:

IP = [10.0.0.1, 10.0.0.2, 10.0.0.3]

then 3 rules will be generated for a rule accessing the variable 'IP',
one for each member of the list. The effect of this is that this now
allows for filtering for multiple values in one field. This can then be
used to support for filtering/allowing of multiple IP addresses per
interface.

An iterator is introduced that extracts each member of a list and
puts it into a hash table which then is passed to the function creating
a rule. For the above example the iterator would cause 3 loops.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>