install libcur-7.30.0.
build by:
$ CPPFLAGS=-I/mingw64/include LDFLAGS=-L/mingw64/lib ./configure --prefix=/mingw64 --disable-shared --build=x86_64-w64-mingw32
$ make
install libiconv-1.14.
build by:
$ CPPFLAGS=-I/mingw64/include LDFLAGS=-L/mingw64/lib ./configure --prefix=/mingw64 --disable-shared --build=x86_64-w64-mingw32
$ make