hgk: ignore ctrl-z as EOF on windows Port a patch from gitk. Original description: Cygwin's Tcl is configured to honor any occurence of ctrl-z as an end-of-file marker, while some commits in the git repository and possibly elsewhere include that character in the commit comment. This causes gitk ignore commit history following such a comment and incorrect graphs. This change affects only Windows as Tcl on other platforms already has eofchar == {}. This fixes problems noted by me and by Ray Lehtiniemi, and the fix was suggested by Shawn Pierce. Signed-off-by: Mark Levedahl <mdl123@verizon.net> Signed-off-by: Paul Mackerras <paulus@samba.org>