CMake: revert un-versioning of libcalamares*.so

The install-bits branch commit 83639b182b
dropped .so-versioning for libcalamares and the creation of the Python-
support symlink. This broke KDE Neon dev-unstable because the embedded
Python can no longer find libcalamares.

Installing unversioned .so's straight to LIBDIR is also not a good thing
(according to Debian), so revert to the original scheme with versioned
.so and a Python-support symlink.

Medium-term fix is to install unversioned straight into LIBDIR/calamares
and fix up the RPATH for the executable.

src/libcalamares/CMakeLists.txt

@@ -83,6 +83,8 @@ add_library( calamares SHARED ${libSources} ${kdsagSources} ${utilsSources} )
 set_target_properties( calamares
     PROPERTIES
         AUTOMOC TRUE
+        VERSION ${CALAMARES_VERSION_SHORT}
+        SOVERSION ${CALAMARES_VERSION_SHORT}
 )
 
 target_link_libraries( calamares
@@ -92,10 +94,18 @@ target_link_libraries( calamares
 
 install( TARGETS calamares
     EXPORT CalamaresLibraryDepends
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
     LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
     ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
 )
 
+# Make symlink lib/calamares/libcalamares.so to lib/libcalamares.so.VERSION so
+# lib/calamares can be used as module path for the Python interpreter.
+install( CODE "
+    file( MAKE_DIRECTORY \"\$ENV{DESTDIR}/${CMAKE_INSTALL_FULL_LIBDIR}/calamares\" )
+    execute_process( COMMAND \"${CMAKE_COMMAND}\" -E create_symlink ../libcalamares.so.${CALAMARES_VERSION_SHORT} libcalamares.so WORKING_DIRECTORY \"\$ENV{DESTDIR}/${CMAKE_INSTALL_FULL_LIBDIR}/calamares\" )
+")
+
 # Install header files
 file( GLOB rootHeaders "*.h" )
 file( GLOB kdsingleapplicationguardHeaders "kdsingleapplicationguard/*.h" )

src/libcalamaresui/CMakeLists.txt

@@ -78,5 +78,5 @@ calamares_add_library( calamaresui
         Qt5::QuickWidgets
     RESOURCES libcalamaresui.qrc
     EXPORT CalamaresLibraryDepends
-    NO_VERSION
+    VERSION ${CALAMARES_VERSION_SHORT}
 )