Fix links on status badges, and add gitter badge.

README

@@ -1,22 +1,19 @@
 Welcome to nanomsg
 ------------------
 
-[![GitHub Release](https://img.shields.io/github/release/nanomsg/nanomsg.svg)]
-[![GitHub License](https://img.shields.io/github/license/nanomsg/nanomsg.svg)]
-[![Linux Status](https://img.shields.io/travis/nanomsg/nanomsg.svg?label=linux)]
-[![Windows Status](https://img.shields.io/appveyor/ci/gdamore/nanomsg.svg?label=windows)]
-[![Issues](https://img.shields.io/github/issues/nanomsg/nanomsg.svg)]
+[![GitHub Release](https://img.shields.io/github/release/nanomsg/nanomsg.svg)](https://github.com/nanomsg/nanomsg/releases)
+[![GitHub License](https://img.shields.io/github/license/nanomsg/nanomsg.svg)](https://github.com/nanomsg/nanomsg/blob/master/COPYING)
+[![Linux Status](https://img.shields.io/travis/nanomsg/nanomsg.svg?label=linux)](https://travis-ci.org/nanomsg/nanomsg)
+[![Windows Status](https://img.shields.io/appveyor/ci/gdamore/nanomsg.svg?label=windows)](https://ci.appveyor.com/project/gdamore/nanomsg)
+[![Issues](https://img.shields.io/github/issues/nanomsg/nanomsg.svg)](https://github.com/nanomsg/nanomsg/issues)
+[![Gitter](https://img.shields.io/badge/gitter-join-brightgreen.svg)](https://gitter.im/nanomsg/nanomsg)
 
 nanomsg library is a simple high-performance implementation of several 
 "scalability protocols". Scalability protocol's job is to define how multiple 
 applications communicate to form a single distributed application.
 
 For more info check the web site: http://nanomsg.org
 
-Build Status
-------------
-Linux (clang and gcc): [![Linux Status](https://travis-ci.org/nanomsg/nanomsg)]
-Windows (Visual Studio 11 and 12): [![Windows Status](https://img.shields.io/appveyor/ci/gdamore/nanomsg.svg?)]
 
 Build it
 --------