• Added optional support for Cpanel::JSON::XS to Mojo::JSON for much better JSON encoding and decoding performance.
  That also means Mojo::JSON can no longer encode the two Unicode whitespace characters u2028 and u2029, since this is
  unsupported by Cpanel::JSON::XS.
  
• Improved Mojo::JSON to encode unknown reference types to "null", consistently with Cpanel::JSON::XS.