Major win32 build system cleanup:

Major win32 build system cleanup:
- Win32: Attempt to move to 100% winsock2 (the include, to be precise),
  this means includes have to be in a very particular order (!)
- Win32: #define _WIN32_WINNT 0x0501 and force our own inet_ntop/pton,
  otherwise you get an ntop runtime error on XP and earlier.
- Win32: Get rid of c-ares includes and library in our tree, and use the
  DLL instead of static LIB, just like we do for ssl and zlib.
- Win32: Get rid of TRE lib and includes
- Win32: reorder includes to fix winsock errors with curl