Update series bugtasks status on stable/* changes
Update series bugtasks status on stable/* changes

Makes update_bug.py Gerrit/LP hook support setting series-specific
bug tasks to FixCommitted status on change-merged to stable/*
branches. Fixes bug 921588.

Also sets "In Progress" on patchset-created to stable/*.

Change-Id: I5e3b7c8d249755a71f3425dd33151764be2a1485

open-switch/infra_puppet-gerrit,dhiana/puppet-gerrit,open-switch/infra_puppet-gerrit,dhiana/puppet-gerrit,open-switch/infra_puppet-gerrit,dhiana/puppet-gerrit