History links 1.3

This class can be used to keep track of the pages navigated by a user, so it can generate back or next links providing a similar effect to the use of the Javascript history.go() function.
It uses sessions to store an array variable that holds the URL of each page of a site that the user accesses. It can limit the number of pages that are kept in the history array.
It may also ignore pages accessed with the POST method or with certain URLs based on options that define exclusion regular expressions. The class can generate links to go back to the last page or the first page that was recorded.
Enhancements:
- The class is completely changed.
- This release adds creation of several objects of a class, a predefined start page, an expanded list of exceptions, and the methods get_history_back, get_history_next, is_history_back (check back one page), is_history_next (check the next page), get_history_backs (go to the first page), get_history_nexts (go to the last page), and get_history_header (go to the previous and next pages using external parameters).
- It adds history "always", and has more compatibility with javascript:history.go() (no checking previous and next pages).
- New methods have been added for the manipulation of history "always".