11863 importer cli (rebased onto develop)



This is the same as gh-1994 but rebased onto develop.

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See: http://trac.openmicroscopy.org.uk/ome/ticket/11863

`importer-cli` from `components/tools/OmeroImporter/scripts` was removed. This resurrects it and places it along with `OMEROinsight_unix.sh` etc. and adds it to the unix and mac zips.


To test:
 * Build the release clients: `./build.py build-dev release-clients`
 * Check that the linux and mac dirs/zips under target/pkgs contain `importer-cli`
 * Execlute `importer-cli` from existing/unzipped directory. Help should be printed.