This adds glfwGetWindowContentScale and glfwGetMonitorContentScale for
querying the recommended drawing scale factor for DPI-aware rendering.
Parts of this patch are based on code by @ferreiradaselva.
Fixes#235.
Fixes#439.
Fixes#677.
Fixes#845.
Fixes#898.
glfwGetMonitorName()’s documentation says “this function returns a
human-readable name”, which “typically reflects the make and model of
the monitor”. We get these two strings in the geometry event, so we
only set the name at this point.
Windows now keep track of the monitors they are on, so we can calculate
the best scaling factor for them, by using the maximum of each of the
monitors.
The compositor scales down the buffer automatically when it is on a
lower density monitor, instead of the previous way where it was scaling
up the buffer on higher density monitors, which makes the application
look much better on those ones.
