Corrected spelling error in comment.
Modified the repl include and require options.

* Now requiring the aws-sdk gem after the $LOAD_PATH
  has been amended.  This allows the user to point
  the repl to a different version of the SDK.

* Now requiring any files specified via -r. This happens
  after the SDK has been loaded and configured.  This
  alows the required library to make use of the SDK.