[fix bug 1029829][fix bug 1029838][bug 1081917] Thunderbird RNA

* Created releasenotes bedrock app
* Migrated firefox release notes views to releasenotes app.
* Added thunderbird releasenotes urls
* Added global.conf RewriteRules for Thunderbird release notes.
* Thunderbird base, release notes, system requirements templates
Remove TOS from homepage: fix bug 1094221

Restore pre-fx10 Webmaker and Appmaker promo tiles
Tweak position of Webmaker logo
Bug 1097399: Update legal-docs submodule.
Merge pull request #2487 from pmclanahan/update-legal-docs-1097399

Bug 1097399: Update legal-docs submodule.
Merge pull request #2449 from jgmize/rm-TOS-content-from-hp

Remove TOS content from homepage: fix bug 1094221
Merge pull request #2364 from glogiotatidis/thunderbird-rna

Thunderbird RNA.