URL path component should use UTF-8 before percent-encoding (that's what
browsers do when you open scrapy/tests/sample_data/link_extractor/linkextractor_latin1.html
and follow the links)
This matches current w3lib v1.14.1
* tests for other link extractors are moved to test_linkextractors_deprecated.py
* in Python 3 Link is converted to use native strings for urls
* minor cleanups