HTMLdoc v1.2.5

This is a bug fix release that fixes some issues and improve validation of the output code:

• Remove alt from list of attributes that can be removed in config::__construct() as this is not valid HTML
• Allowed the attribute token to consume any extra following quotes to prevent capturing being offset when the input HTML is incorrect in htmldoc::$tokens
• Fixed bug in custom::parse() where <script> is allowed to start with an opening HTML comment, a leftover from the days when browsers didn't know what javascript was, but is still legal, it will now be removed by default
• Fixed bugs in doctype::parse() where there were no tokens to capture anything in quotes, which has now been added to htmldoc::$tokens. It now stores the components in an array, and normalises whitespace
• Added minifications to doctype::minify to lowercase directives in the doctype and convert quotes
• The target attribute will now be removed if it is empty
• Added tests