Add spray-client to SBT library dependencies.

spray 1.2.1 is chosen because it is built against Scala 2.10.3 and Akka 2.2.4.
See http://spray.io/project-info/current-versions/#current-versions for further
information.

Also explicitly add Akka 2.2.4 to build.sbt because the Akka version used by
Play framework is 2.2.1. This evicts the older version.
Add GameClientConsole.

GameClientConsole is a command line tool to test Beyond actions. After entering
username and password, we can request actions with action URL and parameters.

GameClientConsole internally uses sprary-client to asynchronously send HTTP
requests. Currently, the base URL is hardcoded to http://localhost:9000, but
this will be changed to a command line argument in the follow-up patch.
Turn off RegexChecker.

RegexChecker prohibits the use of "println" everywhere. So we can't use
Console.println too. Turn this check off to allow Console.println.