Add support for macros

Closes #270

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Note that recursive macros are not yet supported.

cmd/micro/util.go

@@ -3,6 +3,8 @@ package main
 import (
 	"os"
 	"path/filepath"
+	"reflect"
+	"runtime"
 	"strconv"
 	"strings"
 	"time"
@@ -217,3 +219,7 @@ func Abs(n int) int {
 	}
 	return n
 }
+
+func FuncName(i interface{}) string {
+	return runtime.FuncForPC(reflect.ValueOf(i).Pointer()).Name()
+}