Passing `--language en', '-l en-US', or `-l en_US` now takes a special
action to not load any translations using the current locale. This
allows the current system UI language not to influence an translations
loaded via the command line override when the native en-US is wanted.
These go wrong too easily with l10n, this ensures the right menu
actions are treated specially on macOS and moved to their "normal"
place on the global system menu.
This allows the Spanish UI translation to work, for now, for all
Spanish speaking locales. If necessary we can make it es-ES if other
translators feel it is not a good base for their Spanish variant. OTOH
if they just need to l10n a few strings then, say for Argentina, then
they can do that in an wsjtx_es_AR.ts and untranslated strings there
will fall back to the ones in wsjtx_es.ts automatically. This happens
because of teh way the application loads multiple translation files in
an order suitable for that to happen.
The Highlight Callsign (13) UDP message now operates in a slightly
different way. The "Highlight last" field, when true valued, causes
all instances of the specified callsign to be highlighted in the
decoding period. This allows external applications to highlight DX
callsigns even when multiple stations are calling them. Before this
was unlikely to work since the external application would have to
respond to Decode (2) UDP messages exceedingly quickly to guarantee
successful highlighting before another decode with the same DX call
was printed. There should be no changes required to external
applications acting as servers to the WSJT-X UDP Message Protocol,
although using the version of the Highlight Callsign (13) with
"Highlight last" should not be required for adhoc callsign
highlighting. It should be reserved for commonly recurring targets and
limited to no more than 100 active highlighting requests at any one
time, otherwise there may be performance impacts on WSJT-X.
