* Core - Keep nodes of missing plugins and the connection an input reads from in node scripts
- Saving a script keeps nodes whose plugin is missing, and their connections, so they come back once the plugin is available again
- Loading keeps the first connection of an input, the one it reads from
- Disabling a node provider only removes the nodes it created, not those of another provider registering the same type
- RemoveNode only raises NodeRemoved for nodes that were in the script
* Core - Fix pin connections, null values and failing nodes
- Connecting pins that are already connected no longer adds a second connection
- Untyped pins turn null into the default value for value types, as intended
- A new InputPin<T> reads its connection right away instead of after its first reset
- Matching a specific enum to a pin of any enum now depends on forgivingEnumMatching
- A node that fails to evaluate sets its outputs to their default values, so it is evaluated once per run and old values don't flow on
* Core - Round Numeric to long and clamp it to the range of an sbyte
RobertBeekman