Attempt recovery from interrupted syscalls

Rarely `send_command` fails with an error similar to

```
Interrupted system call - /tmp/run_loop20141101-1611-17aghro/repl-cmd.pipe when running command 
(uia.tapOffset('{:x 152 :y 101.5}');uia.keyboard().typeString('damnyouautocorrect');) via strategy host.
```

This pull request attempts to recover from this failure by allowing the interruption. We first assume the command was correctly received and try awaiting a reply. If that fails we retry sending the command entirely.