Update to 1.0.6 and switch to cdecl calling convention
    
    - Update to 1.0.6
    - Export all symbols using the cdecl calling convention instead of
      stdcall as it is also done by various other downstream distributors
      (like mingw.org and gnuwin32) and it resolves various autoconf and
      cmake detection issues (RHBZ #811909, RHBZ #812573)
    - Added -static subpackages (RHBZ #665539)