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.

Gopkg.lock

@@ -7,13 +7,6 @@
   revision = "2600fb119af974220d3916a5916d6e31176aac1b"
   version = "v1.0.1"
 
-[[projects]]
-  branch = "master"
-  name = "github.com/alecthomas/log4go"
-  packages = ["."]
-  revision = "9c17fbb2767ccbdda78584f28d545c44a4b29c4f"
-  source = "https://github.com/mattermost/log4go.git"
-
 [[projects]]
   branch = "master"
   name = "github.com/armon/go-metrics"
@@ -511,6 +504,31 @@
   packages = ["."]
   revision = "a0b114877d4caeffbd7f87e3757c17fce570fea7"
 
+[[projects]]
+  name = "go.uber.org/atomic"
+  packages = ["."]
+  revision = "8474b86a5a6f79c443ce4b2992817ff32cf208b8"
+  version = "v1.3.1"
+
+[[projects]]
+  name = "go.uber.org/multierr"
+  packages = ["."]
+  revision = "3c4937480c32f4c13a875a1829af76c98ca3d40a"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "go.uber.org/zap"
+  packages = [
+    ".",
+    "buffer",
+    "internal/bufferpool",
+    "internal/color",
+    "internal/exit",
+    "zapcore"
+  ]
+  revision = "eeedf312bc6c57391d84767a4cd413f02a917974"
+  version = "v1.8.0"
+
 [[projects]]
   branch = "master"
   name = "golang.org/x/crypto"
@@ -607,6 +625,12 @@
   revision = "41f3572897373c5538c50a2402db15db079fa4fd"
   version = "2.0.0"
 
+[[projects]]
+  name = "gopkg.in/natefinch/lumberjack.v2"
+  packages = ["."]
+  revision = "a96e63847dc3c67d17befa69c303767e2f84e54f"
+  version = "v2.1"
+
 [[projects]]
   name = "gopkg.in/olivere/elastic.v5"
   packages = [
@@ -635,6 +659,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "a6a107c250033694b6d11085333da149e3e1171da3c23ce5bc9362148adef141"
+  inputs-digest = "4f92b22eac4e8efa0aa098a6b1f1599ab087160296bd5fb74a9fad5366bbe1bc"
   solver-name = "gps-cdcl"
   solver-version = 1