Customising skill tree.

[Tree3324417]

Currently, all skills in the skill tree can be changed in terms of value, but it would be nice to be able to customize it further, such as being able to add/remove skill nodes (right now only doable with Exceed the limit node), define new skill nodes/unlock condition nodes at least based on existing ones and being able to change node dependencies.

[Zen9890]

Also max ammount of perks that is defined by modder will be nice too for skill trees designed arround choosing limited ammount of perks