Version bump to 0.6.0-beta-1.
Add the `include` and `exclude` arguments for the authors widget, which are new arguments for `wp_list_authors()`.
Add the `theme_location` argument to the Nav Menu widget.  This allows users to simply choose the menu they have assigned to a specific location.
Make sure widgets have defaults set so that no undefined index notices pop up when using the_widget(), the theme customizer, or some other method that may come along.
Use get_registered_nav_menus() to get a list of the theme's registered nav menu locations. Use this list to create a drop-down select for choosing the 'theme_location' option in the Navigation Menu widget.
Correct the 'classname' for all widgets, which somehow got reverted at some point.
Make sure the Calendar widget has a default title when added via the customizer or called via the_widget().
Add wrapper `<p>` for categories when there's no style.
Eliminate the use of extract() in accordance with new WP core coding practices. http://core.trac.wordpress.org/ticket/22400
Update copyright date in files.
Update inline docs and remove trailing "?>" from files.
Code formatting updates.
Drop the old search widget options. This has needed to be done since the introduction of get_search_form(), which allows plugins to do some nifty things with search forms. Let's not get in their way.
Update code formatting in main plugin file.
Plugin header update.  Add the "Domain Path" header.
Sanitizing and validating like a champ. A complete overhaul of the update() methods for all widgets to give them smarter logic when sanitizing data.
Use the newer HTML5 "number" input type for inputs where users are just entering a number.
Use the HTML5 "url" input type for widget options that require a URL.
Placeholders! Placeholders! Placeholders! It's like free instructions on how to use form fields without having to explain it all out.
The `limit` argument for wp_get_archives() cannot be 0.