Added Multi-Language Support

* Added Multi-Language Support.
* Added Russian translation.
* Created .POT file.
Fixed Additional Styling Description.
Fixed Project ID in .PO file.
Fixed TextDomain in Forms.
Fixed dot after Logout Link.
Corrected WP-Admin Menu Text.
Refactored "load_plugin_textdomain".
Improved logic of textdomain loading.
Content can now be placed above or below login or register form, #22.
Adding support for spanish translation, #25
WordPress 3.9 compatible, #26
Redirect is handled in 1 location, start of JS clean-up, #20
Bug: Registration button no longer shows clickable cursor when fields are empty, they are also required using html5, #27
Merge pull request #1 from zanematthew/master

Update from original repository