Release 0.6.0

Please see changelog diff
Here's another pass at the description, @lhazlewood and @omgitstom  please review:

#### ID Site Improvements ####

We recently added Single Sign On (SSO) support to our [ID Site Feature](http://docs.stormpath.com/guides/using-id-site) and this SDK release adds a `logout: true` option to the ` application.CreateIdSiteUrl([options],cb)` method.  When this option is used  the user’s SSO cookie will be destroyed and the user will be immediately redirected to the specified `callbackUri` where the `idSiteResult` has a new `status` property which will be the value of `'LOGOUT'`