[fix] import path for FromStr
Reexport enums variants

With https://github.com/rust-lang/rust/pull/18973 merged enum variants are namespaced. They should be reexported or used like Enum::Variant.
Import num::Int
Fix deprecation warnings
Fixing memory leaks
Improve EventLoop IO interest handling

* Change io::read/write to not use a loop
* Return the count of bytes read / written
* Allow specifying IO interests when registering
* Add EventLoop#reregister and EventLoop#register_opt
Add a .deregister() method to the event loop.

Closes #29
Merge remote-tracking branch 'markuskobler/master'
Fix reregister / deregister semantics on kqueue
Fix compilation errors due to enums namespacing.
Borrow mutable references with Slab#get_mut
Implement Unix domain sockets support
Vendor mpmc queue as BoundedQueue

Fixes #62
Track Rust master
added read_slice and write_slice to the IoReader and IoWriter traits and all implementations thereof

cleaned up whitespace
Fallout of Copy being opt-in
Fix warnings