Fixup invalid JSON files.

Apparently, my newer Qt is more forgiving than older versions. Still,
the files I committed did not validate against JSON syntax rules. This
is now fixed with this commit.
Don't include unistd.h

Just don't use 'isatty' on Windows, it's a) deprecated, b) does
something entirely different than on Unix

Also see:
http://stackoverflow.com/questions/3648711/detect-nul-file-descriptor-isatty-is-bogus
debugger: BreakpointModel: do not send redundant change reports for the error text

Note that we still emit the signal every time that a non-empty error text is set,
because we assume that such a call with the same error text indicates that an
identical error happened again.
More debug output for startup time measurements