Updated rails from 4.0.1 to 4.0.2

This fixes vulnerabilities CVE-2013-6414 and CVE-2013-0155. For more details see:

http://seclists.org/oss-sec/2013/q4/400
http://seclists.org/oss-sec/2013/q4/403
Updated aws-sdk gem from 1.25.0 to 1.29.0

This removes the dependency limitation "nokogiri<1.6.0", which enables us to upgrade other gems that depend on recent nokogiri versions (feedzirra mostly).
Updated feedzirra from 0.2.0.rc2 to 0.5.0.

This pulls other dependency upgrades, most important among them:

- sax-machine from 0.2.0.rc2 to 0.2.1
- nokogiri from 1.5.10 to 1.6.0
Updated kaminari gem from 0.14.1 to 0.15.1
Updated uglifier gem from 2.3.1 to 2.3.2
Updated launchy gem from 2.4.0 to 2.4.2