Squashed commit of the following:
commit 0097cf1694300c1bbd040529ddc1583dd3c9ae4c
Author: Matt Wilson <matthew@synesis.com.au>
Date: Mon Nov 4 18:02:59 2024 +1100
`frequency_map` : ~ now default-specialised on `frequency_map_traits_unordered` when compiling with C++11+
commit ece3ea3fdc62e8b19aab54d33ada4fb0d494941f
Author: Matt Wilson <matthew@synesis.com.au>
Date: Mon Nov 4 17:57:26 2024 +1100
**test.performance.stlsoft.frequency_map** : ~ improved reporting of results ; ~ now uses `stlsoft::std_chrono_hrc_stopwatch`