Merge branch 'rs/color-grep'

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