add a few annotations in the spi-annotations project that we can use to annotate endpoints so that we can automatically generate HTML documentation for how to configure them; rather like maven goals work. See CAMEL-6304 for more details. The annotations are in a separate project, spi-annotations - as it makes APT+maven much happier that way; the annotations get included in camel-core as well

git-svn-id: https://svn.apache.org/repos/asf/camel/trunk@1470837 13f79535-47bb-0310-9956-ffa450edef68