bug#6926: 24.0.50; widget-button-face should not be bold

[Drew Adams]

At least on MS Windows, bold is far too ugly for this face.  There is no
reason to make it bold.
 
Arguably, it is not too bad for the default font.  But it is terrible
for many fonts, at least on MS Windows.  Look at Lucida Console, for
example (attached).
 
In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2010-08-16 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.4) --no-opt --cflags
-Ic:/imagesupport/include'

bug-ugly-widget-button-face.png
Description: PNG image