Upgraded to latest Rust-Empty
Merge pull request #190 from bvssvni/master

Upgraded to latest Rust-Empty
Unconst all the FFI calls.

This was done by https://github.com/bjz/glfw-rs/pull/182. However, the
original FFI calls were all incorrectly using `*`. They now match the C
headers: `*mut T` is used when C uses `*T` and `*const T` is used when C
uses `const T *`.
Fix travis
Merge pull request #192 from bjz/fix-travis

Fix travis
Merge pull request #191 from metajack/un-const

Unconst all the FFI calls.
Propagate *mut binding changes into wrapper
Merge pull request #194 from bjz/mutify

Propagate *mut binding changes into wrapper
Add a monitor example, and add more documentation relating to monitor handling
Prevent build script from confusing Cargo

It seems that re-generating link.rs in .build.sh confuses Cargo into
thinking that the code has changed and needs to be rebuilt. This commit
changes the build script to only generate link.rs, if it doesn't already
exist, thereby fixing this problem.
Merge pull request #198 from hannobraun/cargo-recompile

Prevent build script from confusing Cargo
Merge pull request #197 from bjz/monitors

Add a monitor example, and add more documentation relating to monitor handling
Update deprecated functions
Merge pull request #201 from bjz/fix-warnings

Update deprecated functions
Updated for latest Rust (75a39e0fb): bitflags now includes deriving(Hash).
Merge pull request #203 from eddyb/master

Updated for latest Rust (75a39e0fb): bitflags now includes deriving(Hash).