True seamless 90 degree rotation

This is kind of a no-brainer... we need a "true" 90 degree rotation component for use with seamless textures.

We know it's practical, since it's already built in to profile gradients. I know there are a few other rotation angles that will also work seamlessly. I've come across a filter for that.

I know we can fake it, but it'd be so much cleaner to have a simple "auto-toggle" in the rotate component that switches between the free rotation mode we have and the desired tileable rotation we could really use.

Any way, just my two-cents for the moment. The thought just kept popping into my head...