Update bare pointers to incl. their mutability.

* `rust` master has replaced bare pointer (`*`) w/ `*mut` and `*const`
Integer literals no longer assume a width.

This code is equivalent to the original, specifying the `int` type.
This type is defined as being pointer-width.
Enums expect `int` but the `posix88` constants are `c_int` (aka `i32`s)
Allow `fn version()` to mutate version numbers in place.

The `rust` allocated memory for the version no. needs to be modified by FFI.

In light of recent changes: we mark the variables as mutable, and make sure
the FFI accepts mutable raw pointers.
setsockopt value does not have to be mutable
Merge pull request #38 from drbawb/feature/fix-bare-ptr

Update for rust-master: specify mutability of bare pointers, and width of integer literals.
Change `to_str()` -> `to_string()` where necessary

* Alters several outdated uses of `to_str()`
* `Message::to_str()` renamed so `Message` continues to impl. `Show`
Update examples w/ change of `to_str()`
Merge pull request #40 from drbawb/feature/to-str-rename

`ToStr` renamed to `ToString`
update to head, switch to cargo
shift over to cargo to build everything
Update to rust HEAD
Add Message::as_bytes
Add Message::as_str
breaking change: tweaks to poll and PollItem

* PollItem should take lifetime to make sure it doesn't outlive a socket
* PollItem.revents should be private and turned into a method
* `poll` should return an `int` as it's the number of signaled events.
Updated to use .to_vec instead of .to_owned.
to_owned() -> to_vec()
Use std::time::Duration
Merge pull request #43 from jedisct1/master

Minor fixes for rust-nightly
Merge pull request #41 from reem/to-vec

Updated to use .to_vec instead of .to_owned.