Update Android build scripts. Remove unnecessary project files

examples/rust/binding-example/Cargo.lock

@@ -0,0 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "binding-example"
+version = "0.1.0"

examples/rust/binding-example/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "binding-example"
+version = "0.1.0"
+authors = ["Joseph Henry <joseph.henry@zerotier.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+#rustc-link-search = ["../../../lib/debug/macos-x86_64/"]
+
+[dependencies]

examples/rust/binding-example/build.rs

@@ -0,0 +1,4 @@
+fn main() {
+	println!("cargo:rustc-flags=-l dylib=c++");
+	//println!("cargo:rustc-link-search=.");
+}

examples/rust/binding-example/src/main.rs

@@ -0,0 +1,10 @@
+
+#[link(name = "libzt", kind = "dylib")]
+extern {
+    fn zts_socket(address_family: i32) -> i32;
+}
+
+fn main() {
+    let x = unsafe { zts_socket(100) };
+    println!("zts_socket() = {}", x);
+}

examples/rust/program.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int zts_socket(int address_family)
+{
+	return -777;
+}

examples/rust/program.h

@@ -0,0 +1 @@
+int zts_socket(int address_family);

examples/rust/program.rs

@@ -0,0 +1,5 @@
+/* automatically generated by rust-bindgen 0.56.0 */
+
+extern "C" {
+    pub fn zts_socket(address_family: ::std::os::raw::c_int) -> ::std::os::raw::c_int;
+}