Artifactory deploy (rebased onto develop)



This is the same as gh-2566 but rebased onto develop.

----

These commits were used directly on c6100-2 in the `/opt/hudson/workspace/OMERO-5.0-release/src` directory to publish jars to http://artifacts.openmicroscopy.org. E.g:
```
eval $(~/ice/ice-multi-config.sh ice35)
ant clean build-default release-hudson -Domero.version=5.0.2-ice35-b26 -Dartifactory.password=SECRET
```
published one set of jars. This done 3 times filled up the `ome.staging` repository with all the jars for release. A single command on artifactory then moved all of those jars to `ome.release`.

As a part of the release build, the only changes needed should be:
 * Add the `release-hudson` target
 * Set the `artifactory.password` property, which can be done securely by using the `-propertyfile` ant argument

For making this work on the merge & latest builds, the repository name will likely need to be made configurable: (**DONE**)

 * `*-release-*` = `ome.staging`
 * `*-latest-*` = `ome.snapshots`
 * `*-merge-*` = `ome.unstable`

/cc @sbesson @jburel @bpindelski