Remove the Reactor::run method (#58)

This commit removes the `Reactor::run` method which has previously been used to
execute futures and turn the reactor at the same time. The tests/examples made
heavy usage of this method but they have now all temporarily moved to `wait()`
until the futures dependency is upgraded. In the meantime this'll allow us to
further trim down the `Reactor` APIs to their final state.

examples/udp-codec.rs

@@ -18,7 +18,7 @@ use futures::{Future, Stream, Sink};
 use futures::future::Executor;
 use futures_cpupool::CpuPool;
 use tokio::net::{UdpSocket, UdpCodec};
-use tokio::reactor::Reactor;
+use tokio::reactor::Handle;
 
 pub struct LineCodec;
 
@@ -39,8 +39,7 @@ impl UdpCodec for LineCodec {
 fn main() {
     drop(env_logger::init());
 
-    let mut core = Reactor::new().unwrap();
-    let handle = core.handle();
+    let handle = Handle::default();
 
     let pool = CpuPool::new(1);
 
@@ -79,5 +78,5 @@ fn main() {
 
     // Spawn the sender of pongs and then wait for our pinger to finish.
     pool.execute(b.then(|_| Ok(()))).unwrap();
-    drop(core.run(a));
+    drop(a.wait());
 }