[libcalamares] Add the first locale-data C++ infra

- Lookup country data based on enum or 2-letter code
 - No data yet, so return only stubs
 - The (generated) data tables are not listed as sources because
   they are #include'd by the API implementation; they're full of
   otherwise-unused static tables, so don't make sense to compile
   separately.
 - While here, tidy up the CMakeLists a bit to reduce the number
   of superfluous variables.

src/libcalamares/CMakeLists.txt

@@ -21,11 +21,14 @@ set( libSources
     JobQueue.cpp
     ProcessJob.cpp
     Settings.cpp
-)
-set( partSources
+    
+    # Locale-data service
+    locale/Lookup.cpp
+    
+    # Partition service
     partition/PartitionSize.cpp
-)
-set( utilsSources
+
+    # Utility service
     utils/CalamaresUtilsSystem.cpp
     utils/CommandList.cpp
     utils/Dirs.cpp
@@ -75,7 +78,7 @@ if( WITH_PYTHON )
     )
 endif()
 
-add_library( calamares SHARED ${libSources} ${kdsagSources} ${partSources} ${utilsSources} )
+add_library( calamares SHARED ${libSources} ${kdsagSources} )
 set_target_properties( calamares
     PROPERTIES
         VERSION ${CALAMARES_VERSION_SHORT}

src/libcalamares/locale/Lookup.cpp

@@ -0,0 +1,51 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Lookup.h"
+
+// No data yet
+
+namespace Calamares
+{
+    
+QLocale::Country countryForCode(const QString& code)
+{
+    return QLocale::Country::AnyCountry;
+}
+
+QLocale countryLocale(const QString& code)
+{
+    return QLocale();
+}
+
+QLocale::Language languageForCountry(const QString& code)
+{
+    return QLocale::Language::AnyLanguage;
+}
+
+QLocale::Language languageForCountry(QLocale::Country country)
+{
+    return QLocale::Language::AnyLanguage;
+}
+
+QPair<QLocale::Country, QLocale::Language> countryData(const QString& code)
+{
+    return qMakePair( QLocale::Country::AnyCountry, QLocale::Language::AnyLanguage );
+}
+
+}  // namespace

src/libcalamares/locale/Lookup.h

@@ -0,0 +1,52 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LOCALE_LOOKUP_H
+#define LOCALE_LOOKUP_H
+
+#include "DllMacro.h"
+
+#include <QLocale>
+#include <QPair>
+
+namespace Calamares
+{
+    /* All the functions in this file do lookups of locale data
+     * based on CLDR tables; these are lookups that you can't (easily)
+     * do with just QLocale (e.g. from 2-letter country code to a likely
+     * locale).
+     */
+    
+    /// @brief Map a 2-letter code to a Country, or AnyCountry if not found
+    DLLEXPORT QLocale::Country countryForCode( const QString& code );
+    /** @brief Map a Country to a Language, or AnyLanguage if not found
+     * 
+     * This is a *likely* language for the given country, based on the
+     * CLDR tables. For instance, this maps Belgium to Dutch.
+     */
+    DLLEXPORT QLocale::Language languageForCountry( QLocale::Country country );
+    /// @brief Map a 2-letter code to a Language, or AnyLanguage if not found
+    DLLEXPORT QLocale::Language languageForCountry( const QString& code );
+    
+    /// @brief Get both Country and Language for a 2-letter code
+    DLLEXPORT QPair< QLocale::Country, QLocale::Language > countryData( const QString& code );
+    /// @brief Get a likely locale for a 2-letter country code
+    DLLEXPORT QLocale countryLocale( const QString& code );
+}  // namespace
+
+#endif