Pycapnp-async

- Bump bundled capnp version to v0.5.3.1

- Make enums hashable (thanks to madeleine-empirical)
- Rework logic on when to build bundled libcapnp. Fixes cross-compilation (thanks to benizl)
- Add traversal_limit_in_words and nesting_limit to RPC classes (thanks to asilversempirical)
- Include class attributes in __dir__. This allows for code completion of class methods (thanks to chaoflow )
- Allow setting lists with python tuples (thanks to chaoflow)
- Fix traversal_limit_in_words and nesting_limit being ignored by `from_bytes` (thanks to plesner)

- Fix bug that prevented event loop from actually being lazy initialized
- Fix possible recursive loop in KjException
- Add `clear_write_flag` method to builder classes

- Make the event loop be lazy initialized
- Add support for segment (de)serialization (thanks to gcv). See to_segments/from_segments methods.
- Fix response objects not referencing parents correctly
- Add test for large reads

- Fix build problem with Cython v0.24
- Include the changelog in the manifest (should fix install problems if pandoc is present)
- Include the traceback in exceptions
- Make sure to encode to utf-8, not the default encoding (thanks to novas0x2a)
- Add --libcapnp-url option in installer to allow installing arbitrary libcapnp versions
- Support mmap objects for reading with from_bytes (thanks to bpiwowar)
- Change read_multiple and read_multiple_packed to copy by default
- Fix mistakenly discarding the file parameter on reads
- Add reraise_kj_exception to the prettyPrint functions. (thanks to kdienes)
- Fix KjException init (missing wrapper). (thanks to E8-Storage)
- Add `result_type` to InterfaceMethodSchema

- Update bundled libcapnp to v0.5.2
- Add warnings for using old restorer methods. You should use `bootstrap` instead
- Fix warning from PyEventPort
- Handle AnyPointers better as arguments to RPC functions
- Add support for using keyword arguments with a named struct in an RPC
- Add bootstrap method to TwoPartyServer
- Add `init` method to lists
- Add support for unix sockets in RPC