0.5.8-pre

[oracle58]

• Refactoring related to (toString() for hash objects #83)
• Refactoring of hbytes (=hex bytes), as naming was not really optimal. IOTA's trits are analogue to our bytes, while their trytes are analogue to our hex string format. We should refer to our counterpart to trytes as txHex, txString or transactionString, and counterpart to trits, as: txBytes or simply bytes.
• attachToTangle, storeTransactions and broadcastTransactions now take param "tx" instead of "hbytes".
• Cleanup and removal of duplicate code in converter