Removed broken initial cursor pos kluges.
Fixed styles for undecorated windows on Windows.
Moved mode setting to after window re-creation.
Fixed documentation for glfwJoystickPresent.
Renamed glfwGetWindowParam to glfwGetWindowAttrib.

Parameters are something specified at creation time and are often
immutable, while many of the values returned by glfwGetWindowParam
reflected current state not controlled by any parameter or hint.
Documentation work.