allow to set number of bits in manager._create_subnet

Change-Id: I2a354bde18122e5c547a7ef5c1c5075a9e147ed8
Yaroslav's special

Change-Id: I640e98920498543d14fe0cba75bb24eabfecf6d7
changes after review

Change-Id: Ia3446afb417f1955fe4daf068c14f5b63379ae01
Merge pull request #12 from kshileev/ipv6

general ipv6 infra with optional net_bits and Yaroslav's special
add Yaroslav's special test to the list of test runner

Change-Id: I8452d3a927590e99af354c05411bdc35869ec6a0
Merge pull request #14 from kshileev/ipv6

add Yaroslav's special test to the list of test runner
Little improvement for subnets test
(cherry picked from commit 3dd8320)

Change-Id: I957e8905ee0aae663ccb33ce95f5c05acb81c440
Merge pull request #15 from kshileev/ipv6

Little improvement for subnets test
Merge pull request #16 from terrrakot/ipv6

Support no gateway option
Merge pull request #17 from terrrakot/ipv6

Support for additional options for ports
add service decorator

Change-Id: Ie5290eae37fddbc371b68e1145e3526eb0dc628d
Merge pull request #18 from kshileev/sniff

add service decorator
DHCPv6 tests