Update to 5.2.0 and various packaging fixes
    
    - Update to 5.2.0
    - Use the generic win32-g++ mkspecs profile instead of win32-g++-cross
      and win32-g++-cross-x64 (as is preferred by upstream)
    - Add support for qtchooser
    - Moved the native tools to /usr/$target/bin/qt5 (qtchooser requires the
      tools to be in an unique folder with their original file names)
      All symlinks in %{_bindir} are updated to reflect this as well
    - Prevent invalid Libs.private references in generated pkg-config files
    - Prevent patch backups from ending up in the mkspecs folders
    - Reorganized and cleaned up the patches