Check for NULL return on glfwGetMonitors
Check for NULL return on glfwGetPrimaryMonitor
Check for NULL return on glfwGetMonitorName
Check for NULL return from glfwGetWindowMonitor.
Implement glfwGetGammaRamp/glfwSetGammaRamp bindings

Get returns a hash of red, green, and blue arrays. The keys are, of
course, :red, :green, and :blue. This seemed like the most reasonable
approach to their implementation, so I went ahead with that.

Set takes the same input - you provide a hash of the same format with
arrays of values, it will pass those onto GLFW via the gamma ramp
struct. Fairly simple. A good way to test this is to do something like

  ramp = (0 ... 32768).step(128).to_a
  monitor.gamma_ramp = { red: ramp, green: ramp, blue: ramp }

which should give the monitor a half-bright linear gamma ramp. It'll
probably be more interesting to do something useful with it, but it's an
easy way to see if it works.

It's recommended you do stick to using 256-length gamma ramps.
Add documentation for get/set_gamma_ramp.
Add gamma= method to Glfw::Monitor.
Align getter/setter names where both exist.

This is mainly for situations where the setter takes more than one value
and the getter returns an array or hash. These will be replaced with in-
Ruby methods or aliases.
Add aliases for getters/setter, setters that take arrays as params.

I think this keeps a nice balance for a Ruby-like API without dropping
the original GLFW API.
Version 0.3.0.
Update README.