Update Logger.php

Fixed little typo
Update Providers\Facebook.php

* Added 'username' which is part of the "Public Profile" based on
http://developers.facebook.com/docs/reference/login/public-profile-and-friend-list/
* Added 'coverUrl' which attempts to retrieve the url to the cover image
Update Facebook.php

Updated case to `coverURL` from `coverUrl`
Updated Providers\Facebook.php

Removed auto fetching of cover url image instead only provide url to the
cover's info xml and let the user retrieve the image from a separate
function call.
Update Providers\Facebook.php

Tweaked variable name to better reflect its content.
Do not overwrite steam nickname if any displayName was set, instead save it to firstName as it's more approriate.
Added user picture to Live provider

For proper functioning of the method getCurrentUserPicture is necessary
to enable CURLOPT_FOLLOWLOCATION in OAuth2Client.php .
Method getUserPicture is AdHoc like facebook picture is.
Updated Disqus API URIs

According to the docs http://disqus.com/api/docs/auth/
* fix Yandex provider (birth date)
As of January 28, 2014, foursquare changed its api:
requests that do not include a v parameter will be rejected.

https://developer.foursquare.com/overview/versioning
Merge branch 'foursquareapi' of github.com:csenf/hybridauth
Merge branch 'master' of github.com:luhla/hybridauth
Merge branch 'master' of github.com:konstantin-komelin/hybridauth
Merge branch 'master' of github.com:waitekk/hybridauth
Merge branch 'master' of github.com:maximerassi/hybridauth
Merge branch 'master' of github.com:crodas/hybridauth
Updated versioning to 2.1.2 and updated changelog
Updating composer with tag alias

Thanks to @rikiless for suggesting this.
Merge commit 'feb90f42d2fca2ab5f7d384f4ab10663964759a0'