Merge branch 'jc/sane-grep'

Recent versions of GNU grep is pickier than before to decide if a file is "binary" and refuse to give line-oriented hits when we expect it to, unless explicitly told with "-a" option. As our scripted Porcelains use sane_grep wrapper for line-oriented data, even when the line may contain non-ASCII payload we took from end-user data, use "grep -a" to implement sane_grep wrapper when using an implementation of "grep" that takes the "-a" option. * jc/sane-grep: rebase-i: clarify "is this commit relevant?" test sane_grep: pass "-a" if grep accepts it