Previously, simple @Grab annotations only worked on classes. This commit
updates the simple @Grab support so that they can be used on anything
that can be annotated with @Grab.

The simplified @Grab support relies upon springcli.properties having
been generated. This commit adds an M2E lifecycle mapping for the
antrun plugin so that springcli.properties is generated as part of an
Eclipse build, thereby making it easier to run tests in Eclipse that
rely upon the simplified @Grab support.