nx-builder must package all kind of available distributions

Looking at http://qa.nuxeo.org/hudson/job/IT-nuxeo-5.4-build/lastSuccessfulBuild/artifact/trunk/release/archives/
There are still unmanaged distributions in http://qa.nuxeo.org/hudson/job/IT-nuxeo-5.4-build/lastSuccessfulBuild/artifact/trunk/release/src/nuxeo/nuxeo-distribution/

All distributions must be packaged into release/archives/

Also, there's no more need to separate package and package-other
package function must open ZIP archive, set executable bit on *.sh and *ctl, add nuxeo-shell, rezip and generate MD5 checksum files.