Merge branch 'rs/color-grep'

* rs/color-grep: grep: prefer builtin over external one when coloring results grep: cast printf %.*s "precision" argument explicitly to int grep: add support for coloring with external greps grep: color patterns in output grep: add pmatch and eflags arguments to match_one_pattern() grep: remove grep_opt argument from match_expr_eval() grep: micro-optimize hit collection for AND nodes