Patch browser: make the Category search work across Authors

[juanriccio]

When I'm looking for a patch by category, even if I enter "CATEGORY=perc" or some similar search string, the results I get are limited to the currently selected author. So if I want to have a bird's view of the whole patch database, I still have to use the mouse and manually go through all the authors. This is unconvenient. It would be nicer if I could see at a glance all the patches that have a Category matching "perc".

[baconpaul]

When I do CAT=perc I get patches spanning multiple authors.