Modify setup.py to support msys2/mingw32/mingw64. Added a simplest libcurl.

Author: buaabyl

mingw32/gcc.txt

@@ -0,0 +1,7 @@
+Using built-in specs.
+COLLECT_GCC=gcc
+COLLECT_LTO_WRAPPER=C:/msys64/mingw32/bin/../lib/gcc/i686-w64-mingw32/6.2.0/lto-wrapper.exe
+Target: i686-w64-mingw32
+Configured with: ../gcc-6.2.0/configure --prefix=/mingw32 --with-local-prefix=/mingw32/local --build=i686-w64-mingw32 --host=i686-w64-mingw32 --target=i686-w64-mingw32 --with-native-system-header-dir=/mingw32/i686-w64-mingw32/include --libexecdir=/mingw32/lib --enable-bootstrap --with-arch=i686 --with-tune=generic --enable-languages=c,lto,c++,objc,obj-c++,fortran,ada --enable-shared --enable-static --enable-libatomic --enable-threads=posix --enable-graphite --enable-fully-dynamic-string --enable-libstdcxx-time=yes --disable-libstdcxx-pch --disable-libstdcxx-debug --disable-isl-version-check --enable-lto --enable-libgomp --disable-multilib --enable-checking=release --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --with-libiconv --with-system-zlib --with-gmp=/mingw32 --with-mpfr=/mingw32 --with-mpc=/mingw32 --with-isl=/mingw32 --with-pkgversion='Rev2, Built by MSYS2 project' --with-bugurl=https://sourceforge.net/projects/msys2 --with-gnu-as --with-gnu-ld --disable-sjlj-exceptions --with-dwarf2
+Thread model: posix
+gcc version 6.2.0 (Rev2, Built by MSYS2 project)