Add last release changes on release page

If we can parse the Changes file with CPAN::Changes, display the last versions
changes, with groups etc
Add dep to cpanfile as well
Only warn of parse failure in debug mode
Merge pull request #889 from omega/omega/release-changes

Add last release changes on release page
Install common::sense in before_install phase.
Bumps Encode from 2.10 to 2.51.