Fix OMERO.matlab polyline/polygon creation

This PR: fixes the x, y ordering during polyline creation using OMERO.matlab and the corresponding unit tests.

To test this PR:
- make sure the [OMERO-merge-matlab-develop/](http://hudson.openmicroscopy.org.uk/job/OMERO-merge-matlab-develop/) job stays green
- check `polyline = createPolyline(x,y)` has the expected points values
- check `polygon = createPolygon(x,y)` has the expected points values

/cc @emilroz