Use save_and_reraise_exception when reraise exception

This fixes reraise in pluign codes.

Closes-Bug: #1279813
Change-Id: Iee174d94c0ce69eb01eb86eea1a903eceb7569d5
Log received pool.status

This patch adds a log statement so we can figure out what status the
lbaas-agent is passing in. This way we can figure out what to prevent.

Change-Id: I1a0f809140127ccb9596d83c97add03a853991a3
Closes-bug: #1295491
Merge "Use save_and_reraise_exception when reraise exception"
Merge "Log received pool.status"