v0.34.0

Changes:

• WASM support #30
• rename AlreadyClosed to AlreadyQuit to be more accurate
• improve correctness of synchronous drops blocking
• added new tokio-multi-threaded feature which enables a faster path for sync drop if on a multi-threaded scheduler, enabled by default, this should be disabled for wasm support
• updated to thirtyfour-macros v0.1.3, which switched to syn v2.0