I've got reports from users that in some cases there can be multiple
identities. Not just one, and in this case, the node type may not be the
first identity. We now iterate over all identities until we either found
one of type "leaf" or "collection".
For example one user reports an ejabberd with PEP case, where the first
identity is of type "pep", the second of type "leaf" and a third one
with category "account" and type "registered".
Also extend DiscoverInfo API with hasIdentity(String, String) and
getIdentities(String, String).
instead of using the old baseName=smack appendix=project.name approach,
we are now going convention over configuration and renaming the
subprojects directories to the proper name.
Having a prefix is actually very helpful, because the resulting
libraries will be named like the subproject. And a core-4.0.0-rc1.jar is
not as explicit about what it actually *is* as a
smack-core-4.0.0-rc1.jar.
SMACK-265
