Adds support for installing Riak through a custom package repository.
Added custom repository support for different platforms. Also, created
an attribute for providing the Enterprise package name.
Remove 1.3.2 Precise hack.
Fix README formatting.
Update CHANGELOG.
Add a suite for testing custom Enterprise package installs.
Merge pull request #92 from basho/hc-custom-repository

Allow Riak package installations from custom repositories.