Added example, template project of AudioOutput provider. Especially the
build.xml file and probably Eclipse builder configuration are worth
looking at / copying.
Fixed a typo in build.xml
Implemented service loadin in Outputs class.
Added DummyOutput implementation to the Playback's classpath.
Factored JavaSound-based audio out as a SPI provider.
Slightly changed build.xml files.
Moved SPI interface to other package.