v1.3.0

• Make arc::spawn and Runtime::spawn accept function objects that return futures, making it not UAF to use lambda captures
• Add a oneshot message channel (arc::oneshot)
• Clearer IoDriver implementation
• Add arc::joinAll(std::vector<Fut>) for joining a dynamic amount of futures
• Add extra assertions to prevent wacky crashes
• Add mpsc::Receiver::empty() and change mpsc::Receiver::drain() to return the messages
• Add a way to set a name for tasks
• Add a way to set the global runtime pointer
• Add blockOn() for BlockingTaskHandle
• Add debug info to tasks when building with the debug feature
• Change poll to require a Context& argument, remove the global context
• Allow choosing which features to compile and which to not
• Throw in debug when recursing too deep
• Refactor all internals to use vtables for ABI stability
• Make a bunch of class members private
• Fix pollable metadata not working on MSVC
• Fix blocking tasks causing use after free when awaited
• Fix shutdown() causing use after frees, abort tasks properly
• Bump fmt and asp to newer versions