Update launchkey.php

edited both launchkey_shortcode() and launchkey_form() functions such that a container div can be styled and placed around the login button generated by [launchkey_login].  Accepted attributes are "class", "id" and "style".
Update launchkey.php

Minor update to function documentation
Update launchkey.php

Added auto-hide functionality to the [launchkey_login] shortcode.  If the "hide" attribute is set to true and a user is already logged in then the button will not be generated.
Update launchkey.php

Spacing fix
Merge pull request #1 from jaketblank/master

Expanded the functionality of the login button shortcode