Set github metadata from the organization's repo

Fixes gh-69
Test::RequiresInternet ensures tests can reach needed wikis
Mark flaky tests as extended
Remove the ability to set the wiki to test against

Nobody uses this, and if you ever did it'd almost certiainly cause
the test suite to fail unless you copy the test corpus from testwiki.
Use HTTPS by default and warn if logging in over HTTP

Also, update all tests that log in to use HTTPS.
Link to API documentation in POD

Fixes gh-63