Adding Windows 32-bit and 64-bit builds

- Basic tests are working
- May need some adjustments to get all tests working
- Cleaned up bundling to take Python arch into account when building
with multiple architectures

capnp/lib/capnp.pyx

@@ -1,6 +1,5 @@
 # capnp.pyx
 # distutils: language = c++
-# distutils: extra_compile_args = --std=c++14
 # distutils: libraries = capnpc capnp-rpc capnp kj-async kj
 # distutils: include_dirs = .
 # cython: c_string_type = str