More array{} work

[avoidwork]

• Refactored array.last() to accept an integer to return an optional array of indices
• Created array.replace() to replace the contents of A with B
• Created array.rest(n) to return a subset of the array from n (offset from the start)
• Created array.rotate(n) to return a new Array with n being shifted to 0 (positive & negative supported)
• Created array.series() which behaves like Python's range(), as a way to generate a custom Array