Make DynamoDBMapper#delete honor the given config

Instead of using this.config.
fix createLayeredSocket

This allows ClientConfiguration proxy settings to be used with
-Dcom.amazonaws.sdk.disableCertChecking
Merge pull request #127 from jcopenha/master

Allow ClientConfiguration proxy settings to be used with -Dcom.amazonaws.sdk.disableCertChecking
Merge pull request #126 from cloudspokes/dynamov2_mapper_ignores_config_on_delete

Make DynamoDBMapper#delete honor the given config