Various (attempted) crash fixes.

Remove global variable, move to Page field.

Log browser history in memory

Add 'pseudolinks' for tab history, apps, & bookmarks.

Extract data for 'pseudolinks', exposing more features.

Extensively refactor to use the CSS engine's counters implementation.

Upload Types modules, & useragent stylesheet with audio cues.

Prevent websites (and userstyles) from overriding the link audio cue.