[PLUGINS] Follow symlinks in plugin discovery
[PLUGINS] Follow symlinks in plugin discovery

Also fix minor formating in log

Change-Id: Ic03e93b821227e36a63599af39dc07f9eb3eb07a
Closes-bug: #1505983

eonpatapon/rally,paboldin/rally,group-policy/rally,gluke77/rally,vganapath/rally,amit0701/rally,vganapath/rally,vganapath/rally,paboldin/rally,eayunstack/rally,eonpatapon/rally,group-policy/rally,amit0701/rally,openstack/rally,gluke77/rally,group-policy/rally,yeming233/rally,openstack/rally,eayunstack/rally,yeming233/rally,openstack/rally,openstack/rally,gluke77/rally,amit0701/rally,paboldin/rally,eayunstack/rally,gluke77/rally,vganapath/rally