Remove debug statements
Always remove player from travellers table before adding them

This should stop there being multiple entries for a player if they have
exited the TARDIS improperly
Allow the default Police Box wall block and lamp to be configurable and allow the sign and lamp to be turned off. These are also now all player preferences.

This should allow servers to set a plain TARDIS as default (as seen in
DW Series 7 finale) and also allow players to change the Police Box
lamp from the default torch (limited to the configured blocks in
block.yml)