Cosmetics: eliminate '\' at line ends.
Fix Chain._get_rules().

If we create a Rule() inside the loop that traverses iptables rules
in a chain, that will call a method in Table that will mess up the
internal cursor in iptables - thus we will only get back the first
rule in the chain. Fix this by creating Rule objects outside of the
loop.
Extend rule iterator test.
Create/remove chain for each test in TestRule.

Use TestRule.{setUp(),tearDown()} to create and flush/remove our test
chain for each test, thus even if a test fails we won't leave rogue
rules and chains in iptables.