Changes:

* Updated to 1.16-pre.2.
* Allowed this version to be loaded in any version of 1.16.
* Print more debugging information about a packet if it failed to read correctly.
    * If "debug" or "debug.request_types" is enabled then this will include a packet payload breakdown.
* Added a config, with two options:
    * "debug": an alternative for "-Dlibnetworkstack.debug=true"
    * "debug.request_types": requests debugging type information from the other side.
* Added a new interface: "IBlockEntityInitialData", which can be used to send custom
   data to each player instead of vanilla's "toInitialChunkDataTag()", and "toUpdatePacket()".
   (Although this is mostly useful for BE's that use LNS exclusively for networking).
* Exceptions thrown while reading a packet will now cause the network 
   connection to be disconnected, as minecraft used to swallow any problems.
