up to 1.9.7, compile fails in gifwriter

gif/gifwriter.cpp: In function 'bool exportGif(const QImage&, const QString&)':
gif/gifwriter.cpp:73:72: error: 'QuantizeBuffer' was not declared in this scope
                    rBuffer, gBuffer, bBuffer, outputBuffer, cmap.Colors);
                                                                        ^
gif/gifwriter.cpp:103:28: error: cannot convert 'const char*' to 'GifFileType*' for argument '1' to 'void EGifSetGifVersion(GifFileType*, bool)'
     EGifSetGifVersion("87a");
                            ^
gif/gifwriter.cpp:105:52: error: too few arguments to function 'GifFileType* EGifOpen(void*, OutputFunc, int*)'
     GifFileType *gif = EGifOpen(&file, saveGifBlock);
                                                    ^
In file included from gif/gifwriter.cpp:32:0:
/usr/include/gif_lib.h:129:14: note: declared here
 GifFileType *EGifOpen(void *userPtr, OutputFunc writeFunc, int *Error);
add giflib5 patch
use our cxx/cxxflags
disable q{cn,jp,kr,tw}codecs for now
shared codecs exists with qt4
Merge branch 'dev': up to 1.9.7