Restore TranslatableSetting.

This was introduced in #851 and #1057 (to 3414efc), fixed
in #1061 (to 22912c8) and removed in 6554c27 for backwards
compatibility reasons (it was hard to maintain the compatibility).
Render TranslatableSettings where required.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
Changelog entry for TranslatableSetting

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
Make TranslatableSettings aware of their names.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
"Default" to the first language if there is no value for the default language.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
Fix the tests; modify language assuming.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
Change the way CONTENT_FOOTER is formatted.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
changelog message for CONTENT_FOOTER_FORMATS

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
BLOG_AUTHOR should not be undefined.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
do not default to the first provided values

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
Make CONTENT_FOOTER_FORMATS work properly.

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
Use the TranslatableSetting framework for NAVIGATION_LINKS

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>