Sidebar shows a link to the RSS feed.
Only show the language of the RSS feed if there is more than one language.
Tag overview: Links to RSS after h1. Only showing language if there is more than one.
Updated changelog.
Merged master from https://github.com/ralsina/nikola/
Merge branch 'master' of https://github.com/ralsina/nikola into feeds2
Merge pull request #415 from okin/fix123

Improved RSS visibility