0.8.0

This release removes allocator support because it suffers from several issues:

1. It misuses the GlobalAlloc trait as opposed to the Allocator api to remain stable. The allocator API would be the best fit but it is currently unstable.

2. Secondly it uses a double Box to pass the GlobalAlloc trait object, because trait objects are fat pointers and across FFI boundaries for the brotli API only thin pointers are accepted. This would be more efficiently done using a ThinBox, which would only allocate once instead of twice.

3. Performance improvements are negligible

I plan to readd support later under a feature gate. Preferably once the required primitives are stabilized.