Register Widget via Static Class Method

Previously this was done indirectly via pseudo namespace singleton,
however the method outlined
[here](http://lkwdwrd.com/register-widgets-static-method) offered a
superior approach

closes #6
Improve Readability of Metabox shortcode box

Previously the shortcode textbox on the Testimonial creation screen may
clip off the last couple characters. Adding `widefat` as a class to the
textbox grows the textbox

Closes #7
update phpdoc

clips the low-hanging fruit of the PHPDoc best practices for WordPress.
More improvements to come in the future.