BLK-145 Add 'update' flag to Queue so that a non-unique incoming signal can *replace* the existing one in the queue

Signed-off-by: Oren Leiman <oleiman@neutral.io>
BLK-179 Adds a test condition for uniqueness update flag

Signed-off-by: Oren Leiman <oleiman@neutral.io>
Merge pull request #2 from nio-blocks/feature/uniqueness

BLK-145 Add 'update' flag to Queue so that a non-unique incoming signal ...