The idea is that it should run for a bit and then let the renderer draw
a frame so that the terminal look responsive. The existing approach
limits the work done using a fixed number elements from the write
buffer so the duration of a frame can vary widely.
This approach looks at the clock to determine when to stop, we basically
allocate an amount of time each frame to write, while the rest can be
used for rendering.
From my tests this change makes the terminal feel a lot smoother.
Juan Campa