General refactor of the cmd package (#3328)

* General refactor of the cmd package

* Address breakage in runCreateUser

* Place "common" functions into cmd.go

cmd/cmd.go

@@ -0,0 +1,38 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+// Package cmd provides subcommands to the gitea binary - such as "web" or
+// "admin".
+package cmd
+
+import (
+	"errors"
+	"fmt"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/setting"
+	"github.com/urfave/cli"
+)
+
+// argsSet checks that all the required arguments are set. args is a list of
+// arguments that must be set in the passed Context.
+func argsSet(c *cli.Context, args ...string) error {
+	for _, a := range args {
+		if !c.IsSet(a) {
+			return errors.New(a + " is not set")
+		}
+	}
+	return nil
+}
+
+func initDB() error {
+	setting.NewContext()
+	models.LoadConfigs()
+
+	setting.NewXORMLogService(false)
+	if err := models.SetEngine(); err != nil {
+		return fmt.Errorf("models.SetEngine: %v", err)
+	}
+	return nil
+}