Make the String method take a LogID instead of a *LogID.
Make the String method take a LogID instead of a *LogID.

This seems to work better with various formatters. Also use the Bytes
method to get the raw bytes.

google/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go