Merge branch 'tb/log-G-binary'

"git log -G<regex>" looked for a hunk in the "git log -p" patch output that contained a string that matches the given pattern. Optimize this code to ignore binary files, which by default will not show any hunk that would match any pattern (unless textconv or the --text option is in effect, that is). * tb/log-G-binary: log -G: ignore binary files