Bitcoin slumps as traders' fears of a "hard fork" Just this month the currency swelled to an intraday high of more than $1,350, but it's come crashing back down as a dispute over the underlying technology threatens to break it into two separate currencies: bitcoin and bitcoin unlimited. Bitcoin transactions are gathered into so-called "blocks", and developers have been embroiled in a long-running debate over the size limit of a block. Currently, there is a one-megabyte maximum on processing batches…