make: only build binaries and their dependencies.

New behavior for -targets:
- Empty only builds default binaries for this requested platform.
- * builds binaries and recursively builds pkg/..., server/..., and
    third_party/... (old empty behavior).
- Or specify the packages you want to build separated by commas.

This should fix the failing build on FreeBSD.

Change-Id: I3e19fd26b7fa5526bb2139487f25a07fa01952c4

make.go

@@ -53,7 +53,7 @@ var (
 	all            = flag.Bool("all", false, "Force rebuild of everything (go install -a)")
 	race           = flag.Bool("race", false, "Build race-detector version of binaries (they will run slowly)")
 	verbose        = flag.Bool("v", false, "Verbose mode")
-	targets        = flag.String("targets", "", "Optional comma-separated list of targets (i.e go packages) to build and install. Empty means all. Example: camlistore.org/server/camlistored,camlistore.org/cmd/camput")
+	targets        = flag.String("targets", "", "Optional comma-separated list of targets (i.e go packages) to build and install. '*' builds everything.  Empty builds defaults for this platform. Example: camlistore.org/server/camlistored,camlistore.org/cmd/camput")
 	quiet          = flag.Bool("quiet", false, "Don't print anything unless there's a failure.")
 	onlysync       = flag.Bool("onlysync", false, "Only populate the temporary source/build tree and output its full path. It is meant to prepare the environment for running the full test suite with 'devcam test'.")
 	// TODO(mpl): looks like ifModsSince is not used anywhere?
@@ -169,7 +169,12 @@ func main() {
 		"camlistore.org/cmd/camtool",
 		"camlistore.org/server/camlistored",
 	}
-	if *targets != "" {
+	switch *targets {
+	case "*":
+		buildAll = true
+	case "":
+		buildAll = false
+	default:
 		if t := strings.Split(*targets, ","); len(t) != 0 {
 			targs = t
 			buildAll = false