nl_tokens: run block update head if valid
pl_tokens: function runBlock ( cb ) { self . runBlock ( { block : block , root : parentState } , function ( err , <mask> ) { if ( err ) { // remove invalid block blockchain . delBlock ( block . header . hash ( ) , function ( ) { cb ( err ) } ) } else { // set as new head block headBlock = block cb ( ) } } ) }