Fix #56
Delete empty space
Fix #8
Fix #40
Formatting
Remove extra function call
Update README.md
Fix #37
Update README.md
Update README.md
Add glfwPostEmptyEvent() support.
Add glfwSetDropCallback() support.

The cgo to Go type conversion in `goDropCB` is unfinished and needs to
be improved.
Update README.md
Update README.md
Update README.md
Add glfwSetCharModsCallback() support.

Related to https://github.com/glfw/glfw/commit/96b12ee50 and
glfw/glfw#305.
Merge pull request #68 from go-gl/feature/add-char-mods-callback

Add glfwSetCharModsCallback() support.
Update README.md

changelog updated