This is just stuff I noticed while working on the wikiheaders updates. A
thorough pass over all the docs would not be terrible, and maybe a simple
script to check for consistency (does everything have a `\since` on it? etc)
might be nice, too.
- Add a globally-accessible function to handle the parsing of filter extensions
- Remove the ability of putting the wildcard ('*') among other patterns; it's either a list of patterns or a single '*' now
- Add a hint to select between portals and Zenity on Unix