Zanata messages

This is part of https://bugzilla.redhat.com/show_bug.cgi?id=1094534

It's basically about removing our dependency on Seam's questionable ability to interpolate EL inside resource bundle messages.
Actually, we're back on Java 1.6 for now, at least for compilation if not runtime:  https://github.com/zanata/zanata-parent/pull/26#issuecomment-48438982

https://github.com/zanata/zanata-server/pull/532 has an implementation of empty Enumeration which should be compatible with Java 1.6.