Client: added initial menu with standard mode and customized mode
Client: for customized mode, added all the piece kinds with carousel
Client: refined menu dialog UI structure
Client: refined customized mode UI structure
Client/Server: changed promotion row to 2 to make keima more useful
Client: custom mode: disable start button while o is not on board
Client: custom mode: disallowed nihu
Client: custom mode: disallowed putting more than one o piece
Client: added toggle button to select which one plays first
Client: added reload mark to restart whenever
Client: small style changes here and there