Hiding Eldritch Invocations without prerequisites

[RobinLefebvre]

In response to issue #209 , added a conditional within the selection styling logic in the Character Builder page. If the current selection is Eldritch Invocations (as defined by the 2nd element of option-path) and does not meet prerequisites (as defined by selectable?), then apply the "hidden" class.

[KingMob]

Hmm, this feels tricky. Um, what's in option-path? What guarantee is there :eldritch-invocations will always be the third item, if present?

For that matter, what guarantee is there that option-path will always have at least 3 items here? nth will throw an exception if it exceeds the bounds. If we're going to look up by index, get is safer, since it will return nil.

Sorry I can't check, don't have time to fire up everything at the moment...

[datdamnzotz]

This will be the breaking changes that @marloso2 wants to put in (really separates orcpub2 from this code) and will introduce compatibility differences between the sites.

[marloso2]

This isn't actually a breaking feature. It just hides any Invocations that aren't selectable, it doesn't change anything about the files. Though, I'm not sure if that's a great idea either way so this should have a toggle, I think