JBother using local mirror for plugins

This feature is maybe not too needed, but it would probably make our users happy: JBother can now use other plugin mirrors than standard one (on www.jbother.org). That means that people running JBother on "closed" networks (like us) can set-up their own plugin mirrors and the users can be up-to-date much easier. I've sent the patch to JBother developers, I hope they will include it into official release.

UPDATE (26.07) : the changes has been included in official JBother release.

Also, I was testing task with Apache ant (separate target makes it even easier to put freshly built SALTPlugin onto our local plugin mirror!). Interestingly, it doesn't work with it 'out-of-the-box': you have to download additional package from Jakarta Commons. After that it is very handy.