add_article.pl now uses xapian instead of mysql.
Fixed a bug about Unique ID in add_article.pl
Updated article.pl to use xapian.
Improved list_articles to use xapian.
add_article.pl now automaticly add the all tag.
Fixed a bug in common.pl.
Updated menu.pl to use xapian.
Updated common.pl to use xapian.
Fixed abug in menu.pl.
Fixed a bug on article.pl.