Prefix the unzipped OMERO.matlab toolbox with version number

The release-clients target used to directly copy the zip file generated by the
release-zip target under components/tools/OmeroM/build.xml. This caused the
unzipped OMERO.matlab toolbox to lose its version number. This commit fixes
this by re-zipping the Matlab target components with a versioned prefix in
release-clients.
Merge pull request #1991 from sbesson/matlab_zip_target

Prefix the unzipped OMERO.matlab toolbox with version number