New logging system (#319)

* First pass at adding new logging system

* NewLogger

* NewLogger

* WIP

* silly bug fix

* :D removed files

* removed old logging interface

* added tests

* added tests

* Started to add new lines to all f calls

* Added subsystem log types

* Logger improvements

* Further performance improvements

* changes to logger and sublogger creation

* Renamed Logging types

* removed old print statement

* changes based on feedback

* moved sublogger types to own file

* :)

* added console as output type

* added get level command

* added get/set log level via grpc command

* added check for output being empty for migration support

* first pass at log rotation

* added log rotation

* :D derp fixed

* added tests

* changes based on feedback

* changed log type

* comments

* renamed file -> fileSettings

* typo fix

* changes based on feedback

* gofmt ran on additional files

* gofmt ran on additional files

config_example.json

@@ -4,10 +4,24 @@
  "globalHTTPTimeout": 15000000000,
  "logging": {
   "enabled": true,
-  "file": "debug.txt",
-  "colour": false,
-  "level": "DEBUG|WARN|INFO|ERROR|FATAL",
-  "rotate": false
+  "level": "INFO|WARN|DEBUG|ERROR",
+  "output": "console",
+  "fileSettings": {
+    "filename": "log.txt",
+    "rotate": true,
+    "maxsize": 250
+   },
+  "advancedSettings": {
+   "spacer": " | ",
+   "timeStampFormat": "02/01/2006 15:04:05",
+   "headers": {
+    "info": "[INFO] ",
+    "warn": "[WARN] ",
+    "debug": "[DEBUG]",
+    "error": "[ERROR]"
+   }
+  },
+  "subloggers": []
  },
  "profiler": {
   "enabled": false
@@ -1322,4 +1336,4 @@
   "checkInterval": 1000000000
  },
  "fiatDispayCurrency": ""
-}
+}