Re-enabling the WSJT-X i18n facilities. This allows translation files
to be created for languages that are automatically used to lookup
translatable strings. To enable a new language the language name must
be added to the CMakeLists.txt LANGUAGES list variable in BCP47 format
(i.e. en_US, en_GB, pt_PT, ...). Do one build with the CMake option
UPDATE_TRANSLATIONS enabled (do not leave it enabled as there is a
danger of loosing existing translated texts), that will create a fresh
translations/wsjtx_<lang>.ts file which should be immediately checked
in with the CMakeLists.txt change. The .ts should then be updated by
the translator using the Qt Linguist tool to add translations. Check
in the updated .ts file to complete the initial translation process
for that language.
To aid translators their WIP .ts file may be tested by releasing
(using the lrelease tool or from the Linguist menu) a .qm file and
placing that .qm file in the current directory before starting
WSJT-X. The translations will be used if the system locale matches the
file name. If the system locale does not match the file name; the
language may be overridden by setting the LANG environment variable.
For example if a wsjtx_pt_PT.qm file is in the current directory
WSJT-X will use it for translation lookups, regardless of the current
system locale setting, if the LANG variable is set to pt_PT or pt-PT.
On MS Windows from a command prompt:
set LANG=pt_PT
C:\WSJT\wsjtx\bin\wsjtx
elsewhere:
LANG=pt_PT wsjtx
This change incorporates a reorganization of the GUI code with
widgets, validators, models, and item delegates being moved to
sub-directories.
Relax the requirements of the ForeignKeyDelegate and related
CandidateKeyFilter classes to allow them to work with constant model
pointers for both referenced and referencing models.