#198 way to reload ONE forced builtin

[Tim Diggins]

see also separate bug - http://sourceforge.net/tracker/index.php?func=detail&aid=1625637&group_id=85796&atid=577329

it would be very handy (when developing with a module which for some reason must be treated as a forced builtin) if there was a mechanism to reload (using the shell as normal) ONLY the one module (currently doing an "apply" which reloads all forced builtins) forces a complete reload of all forced builtins (which only happens once and endures across eclipse restarts) and takes several minutes.