Start factoring out go specific parts of the parser
Start factoring out go specific parts of the parser

Parser now uses generic types.
value.String split into String and GoMarshalledString.

tpukep/caps,zombiezen/go-capnproto2,hodduc/go-capnproto2,zombiezen/go-capnproto,jmckaskill/go-capnproto,hodduc/go-capnproto2,zombiezen/go-capnproto2,zombiezen/go-capnproto