work

Improvements:
- Attrib Ramp now supports a few auto- or "pseudo-" attributes (e.g. for `auto:ageNormalized` it calculates normalized particle age). It is both convenient and efficient (especially for very large particle sims). More auto-s could follow.
- Waypoint can now clean up after itself: if deleted from the UI, by default it asks the user if it should delete its output folder as well (so there won't be any leftover files). There's a more aggressive "cleanup-on-exit" mode which can also be useful in certain situations.
Bug fixes:
- Space Partition SOP

Galleries:
- These are similar to presets but they can't be applied to existing nodes -- they have to be drag-and-dropped into the network view. The _great_ thing is that they work with subnets (so "mini-networks" can also be saved if packed into a subnet)