This reverts commit 70d6e16f, reversing
changes made to ea4db3bc.

Seems to be a code merge done by mistake.

Shelling out was there for authors convenience, but we are
rather going to have the tag or SHA1 always in RAILS_VERSION
and if the environment variable is blank, then just use
"local" as a reminder that you are just working locally.

The docs server has been updated to set the long SHA1 in
RAILS_VERSION when generating edge guides.

This reverts commit f5b9ed4f.

REASON: Translation work can not be done in the docrails repository

* Passing edge information to the views fixes the lack of the edge badge
and sets the appropriate welcome page on edgeguides.rubyonrails.org.
* Changes in the welcome message to hyper link the rails tree based on
the version.
* Mention the Amazon url from where kindlegen can be downloaded.