Bump version.
Write function that determines if a python expression is constant.

This will be improved as incremental screen language work
continues, but this is a start.
Ensure the projects directory is valid before using it.

See #304.
update japanese
update japanese
Merge pull request #305 from kyouryuukunn/update_japanese

Update Japanese translation
Merge branch 'maintenance/6.17'
Merge branch 'maintenance/6.17'
use double colons to show codes correctly
Use __() to show translated texts of the position picker
Make console translatable
Update Japanese translation for console
Use double colons to show code correctly.

Merge remote-tracking branch 'origin/doc-doublecolon' into maintenance/6.17
I18n fixes and translatable console.

Merge remote-tracking branch 'origin/system-translations' into maintenance/6.17