introduce xencl for high-level interaction with xen

xencl/examples/simple.rs

@@ -0,0 +1,9 @@
+use std::collections::HashMap;
+use xencl::{XenClient, XenClientError};
+
+fn main() -> Result<(), XenClientError> {
+    let mut client = XenClient::open()?;
+    let entries: HashMap<String, String> = HashMap::new();
+    client.create(2, entries)?;
+    Ok(())
+}