Resource constructors now accept a hash of client options.

If you do not specify a `:client` option, then the options
hash is used to create a client.

    instance = Aws::EC2::Instance.new(id:'12345678', region:'us-west-2')
    instance.client.config.region
    #=> 'us-west-2'
Fixed an issue that caused a JRuby test failure.
Added feature note to changelog.
Added client helper methods to the REPL.
Removed the two deprecated helpers for the 2.0.0 release of `aws-sdk-core`
Disabled a fragile test that needs to be reworked.