Added recipe for winsock2 and target_os to dependency conditions.

recipes/winsock2/recipe.py

@@ -0,0 +1,23 @@
+
+
+import os
+from SCons.Script import *
+
+
+def available(env: Environment):
+    if os.name != 'nt':
+        return 'Winsock2 is only available on Windows.'
+
+def versions(env: Environment, update: bool = False):
+    if os.name == 'nt':
+        return [(0, 0, 0)]
+    else:
+        return []
+
+def dependencies(env: Environment, version) -> 'dict':
+    return {}
+
+def cook(env: Environment, version) -> dict:
+    return {
+        'LIBS': ['Ws2_32']
+    }