Add methods to obtain the current config file from the robot

[arjvik]

Using this commit:

String configName = RC.config().getName();

You can actually do several interesting things with the RobotConfigFile and RobotConfigFileManager objects (that's why I left them accessible). the RobotConfigFile allows you to obtain an XML parser of the actual current configuration, as well as determine it's file path, so you can modify it and reload the config during robot operation (doing that during an OpMode would probably mess stuff up though). The RobotConfigFileManager is more of an implementation detail of the RC phone (hence why I left it accessible only from the activity) but can let you get finer control over how configurations are parsed and selected.