Remove exclusion of dumps.wikimedia.org

dumps.wikimedia.org is currently excluded from the Wikimedia ruleset, but it supports SSL. There might be a reason I am not aware of to exclude it, but it does not appear to be so.

Some of the other subdomains excluded redirect to dumps.wikimedia.org. It might be worth it to redirect them directly to dumps.wikimedia.org and enable SSL at the same time to avoid a request being sent without SSL to the subdomain first.
Remove exclusion of wiki-mail.wikimedia.org

wiki-mail.wikimedia.org is a redirect to list.wikimedia.org, but it supports SSL, so it does not need to be excluded.
Secure cookies on all Wikimedia wikis

It appears that all Wikimedia wikis support secured cookies correctly, although I have not tested thoroughly. The rules added here enable them on all Wikimedia websites that are wikis. The other websites would need to be evaluated separately to make sure they really do support secured cookies, so they are ignored.
Remove the *.m.wikipedia.org target

The *.m.wikipedia.org target is not necessary because *.wikipedia.org is already included.
Add rule for three wmflabs.org subdomains

The three subdomains of the Wikimedia Tool Labs website that are added to the targets here seem to support SSL. No other subdomain was looked at, but there might be some other subdomains I am not aware of that might or might not support SSL. wmflabs.org itself does not support SSL.
Exclude three subdomains of wikimedia.org

The three subdomains of wikimedia.org added to the exclude declaration in this commit (labs-ns0, labs-ns1 and virt0) redirect to Wikitech’s homepage and do not support SSL, so they need to be excluded.
Reorganize targets

The targets are divided in groups separated by descriptive comments and sorted alphabetically by host.
Merge pull request #223 from rastus-vernon/wikimedia-ruleset-refinements

Refinements to the Wikimedia ruleset