Bug#506366: move api docs to a separate package

[Adam Heath]

package: libjdom1-java
version: 1.0-4
severity: minor

It's poor taste to include the api documentation alongside the code;
packages that only require the library end up having to have the docs
installed as well.  This increases the disk space usage on production
servers.

Please split the docs into a separate package, to solve this problem.