Structured logging (#8673)

* Implementing structured logging

* Changes to en.json to allow refactor to run.

* Fixing global logger

* Structured logger initalization.

* Add caller.

* Do some log redirection.

* Auto refactor

* Cleaning up l4g reference and removing dependancy.

* Removing junk.

* Copyright headers.

* Fixing tests

* Revert "Changes to en.json to allow refactor to run."

This reverts commit fd8249e99bcad0231e6ea65cd77c32aae9a54026.

* Fixing some auto refactor strangeness and typo.

* Making keys more human readable.

utils/i18n.go

@@ -10,7 +10,7 @@ import (
 	"path/filepath"
 	"strings"
 
-	l4g "github.com/alecthomas/log4go"
+	"github.com/mattermost/mattermost-server/mlog"
 	"github.com/mattermost/mattermost-server/model"
 	"github.com/nicksnyder/go-i18n/i18n"
 )
@@ -67,7 +67,7 @@ func InitTranslationsWithDir(dir string) error {
 func GetTranslationsBySystemLocale() (i18n.TranslateFunc, error) {
 	locale := *settings.DefaultServerLocale
 	if _, ok := locales[locale]; !ok {
-		l4g.Error("Failed to load system translations for '%v' attempting to fall back to '%v'", locale, model.DEFAULT_LOCALE)
+		mlog.Error(fmt.Sprintf("Failed to load system translations for '%v' attempting to fall back to '%v'", locale, model.DEFAULT_LOCALE))
 		locale = model.DEFAULT_LOCALE
 	}
 
@@ -80,7 +80,7 @@ func GetTranslationsBySystemLocale() (i18n.TranslateFunc, error) {
 		return nil, fmt.Errorf("Failed to load system translations")
 	}
 
-	l4g.Info(translations("utils.i18n.loaded"), locale, locales[locale])
+	mlog.Info(fmt.Sprintf("Loaded system translations for '%v' from '%v'", locale, locales[locale]))
 	return translations, nil
 }