override CC/CXX when using a special compiler)
 - the RPM should now build on AMD64 and IA64, too


support-files/MySQL-shared-compat.spec.sh:
   - use %_libdir macro instead of hardcoded value (required on AMD64,
     where %_libdir is /usr/lib64 instead)
support-files/mysql.spec.sh:
   - removed the GIF Icon (file was not included in the sources anyway)
   - removed unused variable %shared_lib_version
   - do not run automake before building the standard binary
     (should not be necessary)
   - add server suffix '-standard' to standard binary (to be in line
     with the binary tarball distributions)
   - Use more RPM macros (_exec_prefix, _sbindir, _libdir, _sysconfdir,
     _datadir, _includedir) throughout the spec file (using _libdir was
     required to be used anyway to be able to build on AMD64).
   - allow overriding CC and CXX (required when building with other compilers)