Add New function for creating errors

Author: Dean Karn

README.md

@@ -1,6 +1,6 @@
 Package errors
 ============
-![Project status](https://img.shields.io/badge/version-1.2.0-green.svg)
+![Project status](https://img.shields.io/badge/version-1.3.0-green.svg)
 [![Build Status](https://semaphoreci.com/api/v1/joeybloggs/errors/branches/master/badge.svg)](https://semaphoreci.com/joeybloggs/errors)
 [![Go Report Card](https://goreportcard.com/badge/github.com/go-playground/errors)](https://goreportcard.com/report/github.com/go-playground/errors)
 [![GoDoc](https://godoc.org/github.com/go-playground/errors?status.svg)](https://godoc.org/github.com/go-playground/errors)

errors.go

@@ -1,5 +1,7 @@
 package errors
 
+import "errors"
+
 var (
 	helpers []Helper
 )
@@ -14,6 +16,10 @@ func RegisterHelper(helper Helper) {
 // Wrap encapsulates the error, stores a contextual prefix and automatically obtains
 // a stack trace.
 func Wrap(err error, prefix string) (w *Wrapped) {
+	return wrap(err, prefix)
+}
+
+func wrap(err error, prefix string) (w *Wrapped) {
 	var ok bool
 	if w, ok = err.(*Wrapped); ok {
 		w.Errors = append(w.Errors, newWrapped(err, prefix))
@@ -73,3 +79,8 @@ func IsErr(err, errType error) bool {
 	}
 	return err == errType
 }
+
+// New creates an error with the provided text and automatically wraps it with line information.
+func New(s string) *Wrapped {
+	return wrap(errors.New(s), "")
+}

stack.go

@@ -114,7 +114,7 @@ func funcname(name string) string {
 
 func st() string {
 	s := callers()
-	f := fr(s, 2)
+	f := fr(s, 3)
 	name := fmt.Sprintf("%n", f)
 	file := fmt.Sprintf("%+s", f)
 	line := fmt.Sprintf("%d", f)