Fixing Windows ffi python example

* Added bat to build Windows i686 and x86_64 libraries
* Added bat file to demonstrate calling the python ffi test
* Updated the python ffi test to load the dll correctly

FFI-tests/ffi_test.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 from ctypes import *
-from sys import exit, platform
+from sys import platform, exit
 
 large_image1_path = "../test_images/sample_01_large.jpg".encode(encoding="utf-8")
 medium_image1_path = "../test_images/sample_01_medium.jpg".encode(encoding="utf-8")
@@ -26,24 +26,24 @@ test_images=[
     large_image4_path, medium_image4_path, small_image4_path
 ]
 
+
 def unsigned64(number):
     return (number & 0xfffffffffffffffff)
 
+
 print("starting ffi test")
 
 # Load the shared library
 lib = None
 if platform == 'win32':
-	path = os.path.dirname(__file__) + "\\pihash.dll"
-	print(path)
-	lib = CDLL(path)
+    lib = cdll.pihash
 elif platform == 'darwin':
     lib = cdll.LoadLibrary("libpihash.dylib")
 elif platform == 'linux' or platform == 'linux2':
     lib = cdll.LoadLibrary("libpihash.so")
 else:
     print('Unrecognized platform ', platform)
-	sys.exit(-1)
+    exit(-1)
 
 
 class PIHashes(Structure):

FFI-tests/run_ffi_test_python.bat

@@ -0,0 +1,2 @@
+SET PATH=%cd%;%PATH%
+python ./ffi_test.py

build_windows_libs.bat

@@ -0,0 +1,3 @@
+cargo clean
+cargo build --target=i686-pc-windows-msvc --release --lib
+cargo build --target=x86_64-pc-windows-msvc --release --lib