Rename Predis\Connection\ConnectionFactory.
Rename Predis\Connection\ConnectionParameters.
Rename Predis\Connection\SingleConnectionInterface::pushInitCommand().

The new name is more explicit as it makes obvious that the commands
added with it will be executed upon connect().
Rename Predis\Connection\AggregatedConnectionInterface.
Update CHANGELOG.
Merge branch 'v0.9/connection-namespace-1'
Trim some more "use" directives in Predis\Client.