Eventing: Dismiss all alerts when an entity is removed.
Eventing: Dismiss all alerts when an entity is removed.

This patch adds dismissal of all alerts for an entity, if
that perticular entity is removed.

Change-Id: I6e33135d1dbd847ff54ef93a20d9b38e3a0888a0
Signed-off-by: Darshan N <d2c6d450ab98b078f2f1942c995e6d92dd504bc8@gmail.com>

skyrings/bigfin,skyrings/bigfin,skyrings/bigfin