Fastq: remove deprecated API

We previously implemented our new style of API, i.e. using Or_error and
Future. Now deleted old functions and error types.
Fastq: improve documentation
Fastq: provide split_name function
Fastq: Illumina-specific support

Parse name strings to Illumina sequence identifiers.
travis: pin cfstream and improve pinning

We are again using unreleased functions of cfstream, so need to pin.
Also pin directly to git repos. We were cloning first unnecessarily.