Add relative path determination and update error output

[TimidRobot]

Description

• Fixes Error output has only filename, which may be ambiguous #16
• Add relative path determination and update error output
• I'm happy to change formatting / structure of error output, just let me know.

Output

The example below includes only a single file, for brevity. If the entire project was scanned, there would be many more errors, but the old output would not indicate which file (all files are named contents.lr).

New Output

Command:

linkcheckMarkdown -ext .lr content/archives/old-tech-blog/entries/issue-tracking-at-codecreativecommonsorg/

Output:

ERROR: 'content/archives/old-tech-blog/entries/issue-tracking-at-codecreativecommonsorg/contents.lr' 'http://code.creativecommons.org/issues' 404
ERROR: 'content/archives/old-tech-blog/entries/issue-tracking-at-codecreativecommonsorg/contents.lr' 'http://learn.creativecommons.org/projects/oesearch' 'Cannot connect to host learn.creativecommons.org:80 ssl:default [nodename nor servname provided, or not known]'
ERROR: 'content/archives/old-tech-blog/entries/issue-tracking-at-codecreativecommonsorg/contents.lr' 'http://code.creativecommons.org/issues/issue7' 404
4.58 seconds to check links

Old Output

Command:

linkcheckMarkdown -ext .lr content/archives/old-tech-blog/entries/issue-tracking-at-codecreativecommonsorg/

Output:

 ('contents.lr', 'http://code.creativecommons.org/issues', 404)

 ('contents.lr', 'http://learn.creativecommons.org/projects/oesearch', ClientConnectorError(ConnectionKey(host='learn.creativecommons.org', port=80, is_ssl=False, ssl=None, proxy=None, proxy_auth=None, proxy_headers_hash=-5849311230535720466), gaierror(8, 'nodename nor servname provided, or not known')))

 ('contents.lr', 'http://code.creativecommons.org/issues/issue7', 404)
4.65 seconds to check links

[scivision]

Implemented in b8aa325