Moved DefaultParametersHandler from fluent to builder package.

This interface makes more sense in the builder package. Also, it is going to be
used there, and we do not want to create cyclic dependencies with the fluent
package.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1545823 13f79535-47bb-0310-9956-ffa450edef68