sim: Naive move of binding into mcuboot-sys

Create a crate `mcuboot-sys` to hold the building and binding of the
mcuboot code.  There aren't any substantive code changes here, just
moving the code into a separate crate.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/sim/src/main.rs b/sim/src/main.rs
index acd15a9..61eb2c0 100644
--- a/sim/src/main.rs
+++ b/sim/src/main.rs
@@ -9,6 +9,7 @@
 extern crate rustc_serialize;
 extern crate simflash;
 extern crate untrusted;
+extern crate mcuboot_sys;
 
 use docopt::Docopt;
 use rand::{Rng, SeedableRng, XorShiftRng};
@@ -19,14 +20,12 @@
 use std::process;
 use std::slice;
 
-mod area;
-mod c;
-pub mod api;
 mod caps;
 mod tlv;
 
 use simflash::{Flash, SimFlash};
-use area::{AreaDesc, FlashId};
+use mcuboot_sys::area::{AreaDesc, FlashId};
+use mcuboot_sys::c;
 use caps::Caps;
 use tlv::TlvGen;