cmd/zoekt: allow multiple arguments (#868)

They are interpreted as AND, ie.

    zoekt a b c

is equivalent to

    zoekt "a b c"

cmd/zoekt/main.go

@@ -23,6 +23,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime/pprof"
+	"strings"
 	"time"
 
 	"github.com/felixge/fgprof"
@@ -164,7 +165,7 @@ func main() {
 	flag.Usage = func() {
 		name := os.Args[0]
 		fmt.Fprintf(os.Stderr, "Usage:\n\n  %s [option] QUERY\n"+
-			"for example\n\n  %s 'byte file:java -file:test'\n\n", name, name)
+			"for example\n\n  %s byte file:java -file:test\n\n", name, name)
 		flag.PrintDefaults()
 		fmt.Fprintf(os.Stderr, "\n")
 	}
@@ -175,7 +176,7 @@ func main() {
 		flag.Usage()
 		os.Exit(2)
 	}
-	pat := flag.Arg(0)
+	pat := strings.Join(flag.Args(), " ")
 
 	if !*verbose {
 		log.SetOutput(io.Discard)