Don't descend past the TD tag.

This filters out the footnotes, such as the one listed at Arabic.

Currently PluralRules doesn't contain a rule for Arabic because of this
bug.
Tweak the plural forms regex to exclude Macedonian note.

There's a note at Macedonian, which causes invalid code to be generated.
Extend the length of the regex to include pt_BR.
Sort rules more.

This makes the rule output identical on each run. Avoids huge diffs when
updating the rule sets.
Merge pull request #34 from rubenv/genplurals-fixes

Genplurals fixes