Remove HAProxy logs on LB delete.

Since a node can be reused when load balancers are cycled through
creation and deletion, we need to remove any logs left from HAProxy
so that an ARCHIVE message will not pick up logs from the previous
LB.

Change-Id: I4c26fc5894dc8df7c6a069d612e7c91f96298d8d
Fix worker doc about case sensitivity.

Change-Id: Ie3c279d902aa01d386550aac7692077e19d91341