2.302 is on it's way to devel. Changelog is:
* added option to change font sizes

I had to make it pretty simple though. It allows you to choose between "default", "smaller" and "larger" options. This is because increasing or decreasing ALL fonts by same amount (1, 2, 3 etc) will cause some troubles (text not fitting etc), so I made it act like this:
- setting larger font; increases the smallest fonts by 2-3 pixels and larger fonts only by 1px
- setting smaller font; decreases the largest fonts by 2-3 pixels and smaller fonts only by 1px

Update (black-plastic-theme) should be available in an hour.