[GH #175] sort.pir benchmark reports how many elements were sorted

This gives us output which can be checked in the benchmarks.t test, such
that the sort.pir test can be added to the benchmarks test suite
[GH #175] Add the sort benchmark to the benchmark test suite
[GH #175] sort_ffa.pir benchmark prints number of elements sorted

It's good to see that a program gives some output to the user, so that we
know that *something* happened.  Now we have this output and can add the
relevant search in the benchmarks.t test suite.
[GH #175] Added sort_ffa.pir benchmark to main benchmark suite
[GH #175] Renamed sort.pir benchmark to sort_fia.pir

This makes it more obvious that this benchmark is for sorting
FixedIntegerArrays in much the same way that sort_ffa.pir benchmarks sorting
FixedFloatarrays
[GH #175] Correct typo in sort_fia.pir POD
[GH #175] Added a sort benchmark for ResizableIntegerArrays
[GH #175] Added a sort benchmark for ResizableFloatArrays
Merge pull request #950 from paultcochrane/ptc/sort_benchmarks

[GH #175] Slightly reorganise current and add new sort benchmarks