python 3, multiple kdz format support

[Waltibaba]

• updated to python 3
  • bytearray shenanigans that worked in python2 fixed
  • print statements (f-strings used where sensible)
  • none/0 comparisons fixed
• unsafe file chunker updated to a better implementation (it went out of bounds and looped forever if partition size in kdz was 0)
• cleaned up outputs when using list partitions flag to not show string null terminators

[techdiwas]

Good to go 😺😸.