#1809 word wrapping should trim excess spaces

[Vince Darley]

pack [text .t -width 12 -height 5 -wrap word -font fixed]
.t insert end "this is not what is normally
called word wrapping"

Would under most norms of word-wrapping produce lines
all left aligned. However the text widget instead
wraps in the middle of a group of spaces and therefore
starts some lines with empty spaces.

See e.g.

http://groups-beta.google.com/group/comp.lang.tcl/browse_thread/thread/a00b6e2a2c07086a