FIXES #1286

 - delete the copy and move constructors
 - adjust tests (which were just interested in simple tr() behavior) to use TZZone instead

 - Just move it to its own function where it can have more documentation
 - Tested on multi-screen setups

SEE #1293

FIXES #1293

 - Put Calamares on the first screen where it fits
 - This is wordy and weird

FIXES #1296

[packagechooser] pre-select default item in packagechooser

 - Add Ukranian translations of zone names. Since I don't write
   Ukranian, add only a translation (er .. in this case, the
   proper original spelling) of Kyiv.
 - Fix spelling in English following UN resolution.
 - Dutch remains unchanged, since as far as I can tell the Dutch
   Government still sticks to the Soviet-era spelling.

FIXES #1298

[initcpiocfg] add usr hook if partition is separate

FIXES #1290

 - List discrete years in copyright
 - Add docstrings
 - Massage detect_plymouth() to return bool (easier in if() context)

FIXES #1284

 - all the TZ location information now lives in the Calamares
   locale service and the TZ list
 - replace the Location class that was local to the timezone
   widget by the TZZone class
 - chase a bunch of small API changes that this needs

 - Split the actual loading of translations into classes
   to encapsulate the loading logic,
 - Build a collection of classes to do the different kinds
   of translation loading,
 - Build a generic function to load something and update a
   static pointer to the translation.

This makes installTranslator() much easier to read, and encapsulates
the type-specific loading somewhere else. While here, add a timezone-
translations loader so that the split-out TZ translations also work.