Write header immediately in AbortWithStatus()

Otherwise, caller needs to invoke WriteHeaderNow himself after
AbortWithStatus(), which is error-prone.

Also modified ErrorLoggerT() such that it always writes log to response
body. Otherwise calling AbortWithStatus() will fail to write body because
c.Writer.Written() is set true by WriteHeaderNow().

logger.go

@@ -28,12 +28,9 @@ func ErrorLogger() HandlerFunc {
 func ErrorLoggerT(typ ErrorType) HandlerFunc {
 	return func(c *Context) {
 		c.Next()
-		// avoid writting if we already wrote into the response body
-		if !c.Writer.Written() {
-			errors := c.Errors.ByType(typ)
-			if len(errors) > 0 {
-				c.JSON(-1, errors)
-			}
+		errors := c.Errors.ByType(typ)
+		if len(errors) > 0 {
+			c.JSON(-1, errors)
 		}
 	}
 }