views_slideshow_swiper 7.x-2.0

Enabled callback function parameters and connected Swiper and Slideshow JS events and callbacks.

• Changed JS constant values so they all reside under Drupal.settings.viewsSlideshowSwiperValues.
• Added JS code to instantiate callback function parameters with user-inputted function bodies.
• Added logic to merge user-defined callback functions with glue code that maps Swiper events to Slideshow callbacks.
• Added a central action dispatcher to map Slideshow events to Swiper callbacks.
• Added logic for parameters with special values (e.g. the integer parameter slidesPerView must also be able to equal 'auto').
• Added a validation function to the configuration form submission to remove settings that are their default value.
• Fixed logic in hook_requirements so the requirements severity levels are set appropriately.
• Fixed a few minor typos.
• Tested against Views Slideshow's default Text Controls, Field Pagers, and Slide Counter.