Free persistence of memory script

Major Features:

1. Headers and their contents to expand/collapse on the page are identified through the use of shared CSS class names for easy set up.
2. Ability to specify which contents should be expanded by default when the page first loads.
3. Specify whether only one content should be open at any given time (collapse previous before expanding current.
4. Enable optional persistence so when the user expands a header then returns to the page within the same browser session, the content state is preserved.
5. Style the two states of the headers easily by setting two different CSS classes to be added to the header depending on whether its content is expanded or collapsed. You can also add additional HTML to the beginning or end of each header, such as an icon image that reflects the current state of the content.
6. Arbitrary links can be defined elsewhere on the page performing the same functions as if the user had directly clicked on a header, such as expand a particular header, toggle a header, or expand all headers within a group.
7. A link from another page linking to the target page can cause the desired headers on the later to expand when loaded, via the URL parameter string.
8. Two event handlers on-in-it() and on-open-close() can be used to run custom code when an Accordion Content first loads and whenever a header is opened/closed, respectively.