Work on UAPI

Cross-platform API (get operation)
Handshake initiation creation process
Outbound packet flow
Fixes from code-review

src/Makefile

@@ -0,0 +1,9 @@
+BINARY=wireguard-go
+
+build:
+	go build -o ${BINARY}
+
+clean:
+	if [ -f ${BINARY} ]; then rm ${BINARY}; fi
+
+.PHONY: clean