Fix Bug 2086 Updating VNF status configurable

This fix allows to set REFRESH_ACTIVE period as config option which
periodically checks the VM status from VIM. Env variable can be set in the
ro container export OSMRO_PERIOD_REFRESH_ACTIVE=-1 to disable VM status updates.
This config parameter allowed to set >= 60 seconds or -1.
Making the stage-releasenotes.sh executable.

Change-Id: I90a859d9b831c1ce24faea4eab12dc998ac655d5
Signed-off-by: aticig <gulsum.atici@canonical.com>