title: Findbugs Maven plugin - findbugs-exclude with multiple projects
body: <p>I've got a multiple project setup, using Maven and the Findbugs plugin.  I need to exclude some files in one of the child projects, so I added it to <code>findbugs-exclude.xml</code>.  That works when I build in the subproject.</p>
  
  <p>My issue comes when I try to build at top level.  Maven is not finding the <code>findbugs-exclude.xml</code> in the subproject.  So it doesn't ignore my errors and fails because of them.  I can put my <code>findbugs-exclude.xml</code> in the top level directory, and the exclusion works.  But that's polluting the top level, and would not be looked upon favorably.</p>
  
  <p>Is there a way to get the Maven plugin to use the <code>findbugs-exclude.xml</code> file from a subdirectory?  Preferably with little to no change at the top level?</p>