Added array max and min functions.

Separate versions for arrays of integers or doubles.  Note: it is the
max or min value that is returned, not its array position.
Added integer array quicksort and insertion sort

Quicksort uses a non-recursive implementation to avoid NetLinx recursion
limit.
array.axi minor indent tidying.
Removed old qsort stub from array.axi
Merge pull request #1 from PsyenceFact/master

Adding array library max/min functions and integer array quicksort(..)