Release 2.4.27  (2.4z + patches)

 - Change vectors to be relative current namespace.
 - Bgexec handling of interp cleanup.
 - Fixes for obvious sourceforge bugs/patches.
 - Internalize OLDCONFIG so Blt works with 8.5+
 - Make config options sub-interp/thread safe.
 - Remove use of bltEmptyStringObj as unsafe.
 - Container arg "-window interpN.win" for embed in subinterp.
 - Update tour.tcl to support all demos and use new -window interpN.win option.
 - Args for tour.tcl: "-tearoff 1" and "-bgexec 1"
 - Config dumps 6th arg (string type) if window name prefix is .__##

