Stop using the com.yammer.* namespace

[codahale]

From the Java tutorial on package naming:

Companies use their reversed Internet domain name to begin their package names—for example, com.example.mypackage for a package named mypackage created by a programmer at example.com.

Name collisions that occur within a single company need to be handled by convention within that company, perhaps by including the region or the project name after the company name (for example, com.example.region.mypackage).