moved vw_explore into explore folder
restructured all explore code into explore/ folder
renamed projects in VS
Renamed explore VS project files
renamed clr_wrapper folder to clr
Renamed MWT to MWTExplorer
renamed choose_action_join_key. renamed all state context to policy params
Moved num_actions parameter from MWT constructor to Initialize() methods
Modified Choose_Action method to use std::string unique_key instead of char*