Added with_lock context manager for any lock
CassScalingGroup using kazoo lock

- setting kz_client to store after kazoo starts
- removed references to basiclock
- updated tests accordingly
with_lock tests added
Kazoo threads is configurable

Setting 100 threads in config.json since each lock operation requires a
thread access
Merge branch 'master' into kazoo_lock
fixed tests
tests updated for store.kz_client check
Have state calculate active/pending/desired capacity
Log convergence events to the audit log when scaling up or down due to config change or policy execution
Leave policy id for now
additional changes before final release
Hack to force policy_id and webhook_id to not be included in audit log in convergence
Merge pull request #468 from rackerlabs/audit-log-convergence-logs

Log convergence events
final changes before release
Merge pull request #467 from rackerlabs/kazoo_lock

Kazoo lock
Mock kz client in rest test case
Merge pull request #471 from rackerlabs/fix_failing_intermittent_test

Mock kz client in rest test case
Merge pull request #469 from rackerlabs/constanzeworking21

Updating GS and Dev Guides and removing references to early access