Updates for PHP8 & GPL, a few IndieWeb TLDs, new functions

overall:

• license CC BY-SA 4.0 (for GPL compat)
• PHP 8 compat
• various other bug fixes, better handling of function params

new file:

• cassis-lab.php — functions that would work well as CASSIS but have no known client-side use-cases

new functions:

• ctype_lower
• stripos
• prepath_of_uri
• segment_of_uri
• fragment_of_uri
• get_absolute_uri
• is_html_type
• xpr_attr_starts_with_has_class
• get_auto_linked_urls

improved functions:

• auto_link_re — new TLDs for IndieWeb sites
• auto_link — link @-domain (e.g. rather than just Twitter handle)

Many bug fixes, function improvements, and new functions since last release!

Numerous minor bug fixes, function improvements, and several new functions:

• array_slice
• protocol_of_uri, hostname_of_uri, path_of_uri, is_http_uri, sld_of_uri, relative_uri_hash
• dt_to_time, dt_to_date, dt_to_ordinal_date
• tw_url_to_username
• fb_url_to_event_id
• auto_space
• trim_leading_urls
• ucfirst (JS-only — exists in PHP itself)

v0.1.16124: Merge pull request #11 from pfefferle/master

update for packagist. "loader" file to be more composer friendly.