Big Commit:
- Set default version to 2.6.13 (this module will now only support 2.6+)]
- Class['redis'] no longer creates a default instance, only manages installation of redis
- Use update-alternatives for redis-cli and redis-server executables
- Remove wget/gcc includes
- Add dependencies requirement: Package['build-essentials'], Package['wget']
- Use upstart over init.d
- Update redis configuration file to latest version in 2.6.13
- Add parameter to enable AOF persistence, parameterize fsync policy