pass a reference to the play_controller to the game_lua_kernel

also expose pointer to whiteboard manager from a public getter in
the play controller
remove last resources:: links from game_lua_kernel
add "lua_chat" to replace chat_message in lua kernel

chat_message, from lua_api.?pp, relies on resources links
move config, vconfig, tstring and helper functions to lua_common

Probably lua_common should be split up further, it's a bit
crowded
refactor lua file ops: use fileops::load, but use kernel pcall
add "synced_context_id"

the plan is to allow non-current-players to send require_random.
make server read "context_id"
every client asks server for random seed.

this breaks mp compability.
count requests instead of synced contexts for require_random
comment fix