building boost with mingw

boost-build

# boost 1.46.1, from msys
$ bootstrap.bat --with-toolset=mingw
$ mv project-config.jam project-config.jam.old
$ sed s/mingw/gcc/g project-config.jam.old > project-config.jam
$ bjam.exe --prefix=C:/boost/boost-1.46.1 -j8
$ bjam.exe install

# boost 1.54.0, from cmd.exe
> boostrap.bat mingw
> b2.exe --prefix=C:\Libs\boost toolset=gcc -j8
> b2.exe --prefix=C:\Libs\boost toolset=gcc -j8 install