[bug 1081917] Fix Thunderbird RNA Apache redirects.

* Fix redirects to web-archive
* Fix redirect to /b/releases/$
Merge pull request #2499 from glogiotatidis/thunderbird-rna

[bug 1081917] Fix Thunderbird RNA Apache redirects.
Redirect /ja/contribute/: fix bug 1091977
Fix Bug 1098535 - Replace lang="en-US" with lang="en" to make the content region-neutral