ANN: yield patch for 4.0 (was sleep patch)

["Thatcher Ulrich" <tu@...>]

I updated the sleep patch for Lua 4.0, turning it into the "yield
patch".  Identical functionality, different name, and a few minor
cleanups of comments.

See "Power Patches" page at www.lua-users.org for details.

-- 
Thatcher Ulrich <tu@tulrich.com>
http://tulrich.com