merge upstream, add tests, full method context

- added benchmarks, and assertions for timeliness
- replaced regex usage in package-name handling with a straight
  comparison to a cached value
- log the fullly-qualified method name, to remove ambiguity
    eg: github.com/fflintstone/yabba.dabba.doo
- clean up possibly-unsafe assumptions about using the standard logger,
  remove global lookup function to enforce safe usage

README.md

@@ -1,4 +1,4 @@
-# Logrus <img src="http://i.imgur.com/hTeVwmJ.png" width="40" height="40" alt=":walrus:" class="emoji" title=":walrus:"/>&nbsp;[![Build Status](https://travis-ci.org/Sirupsen/logrus.svg?branch=master)](https://travis-ci.org/Sirupsen/logrus)&nbsp;[![GoDoc](https://godoc.org/github.com/Sirupsen/logrus?status.svg)](https://godoc.org/github.com/Sirupsen/logrus)
+# Logrus <img src="http://i.imgur.com/hTeVwmJ.png" width="40" height="40" alt=":walrus:" class="emoji" title=":walrus:"/>&nbsp;[![Build Status](https://travis-ci.org/sirupsen/logrus.svg?branch=master)](https://travis-ci.org/sirupsen/logrus)&nbsp;[![GoDoc](https://godoc.org/github.com/sirupsen/logrus?status.svg)](https://godoc.org/github.com/sirupsen/logrus)
 
 Logrus is a structured logger for Go (golang), completely API compatible with
 the standard library logger. [Godoc][godoc]. **Please note the Logrus API is not
@@ -77,7 +77,7 @@ The simplest way to use Logrus is simply the package-level exported logger:
 package main
 
 import (
-  log "github.com/Sirupsen/logrus"
+  log "github.com/sirupsen/logrus"
 )
 
 func main() {
@@ -88,7 +88,7 @@ func main() {
 ```
 
 Note that it's completely api-compatible with the stdlib logger, so you can
-replace your `log` imports everywhere with `log "github.com/Sirupsen/logrus"`
+replace your `log` imports everywhere with `log "github.com/sirupsen/logrus"`
 and you'll now have the flexibility of Logrus. You can customize it all you
 want:
 
@@ -97,7 +97,7 @@ package main
 
 import (
   "os"
-  log "github.com/Sirupsen/logrus"
+  log "github.com/sirupsen/logrus"
 )
 
 func init() {
@@ -146,7 +146,7 @@ application, you can also create an instance of the `logrus` Logger:
 package main
 
 import (
-  "github.com/Sirupsen/logrus"
+  "github.com/sirupsen/logrus"
 )
 
 // Create a new instance of the logger. You can have any number of instances.
@@ -199,9 +199,9 @@ Logrus comes with [built-in hooks](hooks/). Add those, or your custom hook, in
 
 ```go
 import (
-  log "github.com/Sirupsen/logrus"
+  log "github.com/sirupsen/logrus"
   "gopkg.in/gemnasium/logrus-airbrake-hook.v2" // the package is named "aibrake"
-  logrus_syslog "github.com/Sirupsen/logrus/hooks/syslog"
+  logrus_syslog "github.com/sirupsen/logrus/hooks/syslog"
   "log/syslog"
 )
 
@@ -226,7 +226,7 @@ Note: Syslog hook also support connecting to local syslog (Ex. "/dev/log" or "/v
 | [Airbrake](https://github.com/gemnasium/logrus-airbrake-hook) | Send errors to the Airbrake API V3. Uses the official [`gobrake`](https://github.com/airbrake/gobrake) behind the scenes. |
 | [Airbrake "legacy"](https://github.com/gemnasium/logrus-airbrake-legacy-hook) | Send errors to an exception tracking service compatible with the Airbrake API V2. Uses [`airbrake-go`](https://github.com/tobi/airbrake-go) behind the scenes. |
 | [Papertrail](https://github.com/polds/logrus-papertrail-hook) | Send errors to the [Papertrail](https://papertrailapp.com) hosted logging service via UDP. |
-| [Syslog](https://github.com/Sirupsen/logrus/blob/master/hooks/syslog/syslog.go) | Send errors to remote syslog server. Uses standard library `log/syslog` behind the scenes. |
+| [Syslog](https://github.com/sirupsen/logrus/blob/master/hooks/syslog/syslog.go) | Send errors to remote syslog server. Uses standard library `log/syslog` behind the scenes. |
 | [Bugsnag](https://github.com/Shopify/logrus-bugsnag/blob/master/bugsnag.go) | Send errors to the Bugsnag exception tracking service. |
 | [Sentry](https://github.com/evalphobia/logrus_sentry) | Send errors to the Sentry error logging and aggregation service. |
 | [Hiprus](https://github.com/nubo/hiprus) | Send errors to a channel in hipchat. |
@@ -306,7 +306,7 @@ could do:
 
 ```go
 import (
-  log "github.com/Sirupsen/logrus"
+  log "github.com/sirupsen/logrus"
 )
 
 init() {
@@ -431,7 +431,7 @@ logrus.RegisterExitHandler(handler)
 ...
 ```
 
-#### Thread safty
+#### Thread safety
 
 By default Logger is protected by mutex for concurrent writes, this mutex is invoked when calling hooks and writing logs.
 If you are sure such locking is not needed, you can call logger.SetNoLock() to disable the locking.