Don't ignore params limit if offset is None

[will-moore]

Fixes #320

To test:

The params limit should not be ignored:

params = omero.sys.ParametersI()
params.theFilter = omero.sys.Filter()
params.theFilter.limit = wrap(1)
images = list(conn.getObjects("Image", params=params))
assert len(images) == 1

I'll add an integration test...

cc @erickmartins @joshmoore

[joshmoore]

I don't assume anyone is depending on this behavior, so 👍 but in general, calling page(0, limit) would achieve the same, right?

[joshmoore]

This looks good to me. 👍 There may be room for clarification in the doc string to specify what takes priority, etc. but that's not directly related to @erickmartins' issue.

[will-moore]

On getObjects() and buildQuery() we have:

 :param params:      omero.sys.Parameters, can be used for pagination,
                            & filtering by owner. Takes precedence over opts.

[jburel]

Thanks
Suggesting to merge and tag 5.11.1