Support timeout and deadline parameters for send

Add support for timeout and deadline parameters when messages are sent
to a message queue. To keep code duplication small, the `utils.rs`
file contains a helper function to parse the `Duration` from the
`String` received from the timeout parameter. Add conflict rules for
the timeout and deadline parameters.

src/main.rs

@@ -7,6 +7,7 @@ mod info;
 mod recv;
 mod send;
 mod unlink;
+mod utils;
 
 use cli::{Command, Opts};