Make GetFeature-Urls ending with & work, change logger to actually use "owslib" namespace

[lordi]

This fixes a bug where a GetFeature URL ending with "&" was incorrectly constructed.

Also while debugging I was missing logs in the "owslib" namespace (as written in the docs). I think the second change in this MR fixes this.

[tomkralidis]

@lordi thanks for the valuable contribution. It turns out that we log as logging.getLogger(__name__) in the library (though we say otherwise in the docs, README and tests). Can you update this PR set the logger to __name__? I'll update the docs/test/README in this regard for consistency. Thanks.