Create entries for players that are present in the save on server
startup to preserving their inventory and fix attempting to reference the
player object after it had been removed in on_player_removed.
When upgrading or downgrading the inventory_sync plugin it's possible
an different structure of the global.inventory_sync table is left behind
which could cause the code to crash when certain sub tables are not
present.
Be more defensive in the initialization of the table to make sure all
sub-tables are present on startup.
* New method avoids all dataloss and prefectly replicates the queue
* Made proper description in readme
* Added packages to make lerna build happy
* Added reference to main readme