initial auth lexer and parser code
initial auth marshal code using protobuf format
initial auth unmarshal code using protobuf format
binary encode/decode with custom format
rename String to Str
compile and fmt errors
workaround issue 8512
parser only looks ahead when necessary

Unit tests pass
minor bugs in auth and go/fmt
minor parsing bugs
add Format(), increase test coverage
add missing copyright
go fmt
allow tpm principals, don't use base64w for keys
add a subprin type
rewrite most code to use pkg auth
rewrite remaining code to use pkg auth
move GenerateAttestation to attestation.go
fixes from tmroeder's review, integrate with other code

all unit tests pass
implement tao_domain.go