ToDo

- Use Bitarrays and not One-Byte-for-a-Bit in javr
- AT90CAN reads back the flash as Bytes. With USB transfers, 
  this is damned slow. Provides some mechanism to queue read requests
- Compress the XC3AN bit files and include into the binary
- More cables
- Cleanup C++ code
- More devices (XC2C, XC95xx (without X))
- Other devices with published 1532 algorithm
- Bitorder for Intel HEX format
- Finer granularity for erasing XCFP
- ... 
- Check Byte Order IHEX versus MCS
- Document cable Database
- Break possible infinite loops, like ProgAlgXC3S::array_program
    do
    jtag->shiftIR(CFG_IN, buf);
  while (! (buf[0] & 0x10)); /* wait until configuration cleared */
- Progress in indicator when writing large bitfiles in legacy mode. Perhaps
  have an indicator thread reading out variables when writing the JTAG bits