16304, 16468, 16577, 17701, 17880, 16051, 16652, 16698
Plus some from the mailing list.
Imported a patch from Eli to allow Cygwin builds to support DOS-style
pathnames.
Revert a fix for $? including non-existent files as it shows a bug
in the Linux kernel build. Give them a release to fix this.
Add some changes from Eli Z. for Windows changes.