Add webhook plugin
Merge pull request #32 from chamerling/master

Add Webhook plugin
use only relative links
let socket.io respect current url pathname
history plugin: make links relative
Merge pull request #33 from koelnconcert/master

use relative urls (to support foward proxies)
* Refactored api.js, now contains only api calls and the check loop
* Refactored server.js so that it can become embeddable as a ndoe module
* created bin/statusdashboard, to be used as a binary app instead of server.js
* created lib/sources, for creating different source check
* created lib/checks, for creating shared checks between sources
* All touched code should now pass standard jshint test
* adding an entry specifying the binary
* shuffled some functions around and added some comments for clarity
* reconfigure, start and stop for the scheduler
* Fixed double-callback issue with statusDashboard check sequence
* new api function: addService and removeService
* some code refactoring to keep module internal variables close to what uses them
* renamed api.start/stop to startChecking/stopChecking
* Updating the package.json a bit, and adding myself as a contributor
* Fixed logging: now uses the same logging strategy as the rest of the app
* Updated the README file
* Bugfix: splice the status object as well to remove it from the stat list
* Adding callback for httpStatusCodeCheck
* Bugfix: incorrect path for static content delivery when used as a node submodule
* Made the code use callback in http and https, instead of calling the controller.emit twice
* bugfix: bin definition was wrong
* Adding possiblility of custom http checks