allow cassandra deb package to replace apache-cassandra1

Patch by paul cannon; reviewed by eevans for CASSANDRA-3480

git-svn-id: https://svn.apache.org/repos/asf/cassandra/branches/cassandra-1.0@1200148 13f79535-47bb-0310-9956-ffa450edef68

debian/control

@@ -11,6 +11,8 @@ Standards-Version: 3.8.3
 Package: cassandra
 Architecture: all
 Depends: openjdk-6-jre-headless (>= 6b11) | java6-runtime, jsvc (>= 1.0), libcommons-daemon-java (>= 1.0), adduser, libjna-java
+Conflicts: apache-cassandra1
+Replaces: apache-cassandra1
 Description: distributed storage system for structured data
  Cassandra is a distributed (peer-to-peer) system for the management
  and storage of structured data.