stop compiling Tags and most apps

We are making broad changes and it was difficult to do so since Tags
depends on every module. Removing it and all the apps that depend on it
will simplify development at this time.

All affected files moved into a tmp/ directory, so we can still
remember the code that needs to be re-incorporated.
Merge branch 'master' of github.com:biocaml/biocaml
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.
bam_alt: heavy changes in API and implementation

the BAM module now uses an special representation of alignment
records, which is hardly parsed. The idea is to avoid unnecessary
parsing like CIGAR, sequence or quality decoding if it's not
necessary.

Also added more tests, which check the contents of alignments.
bgzf: massive bug correction (also in bam)

Bgzf:
- incorrect write endianness
- check valid argument in bgzf.input_string
- incorrect isize in block
- incorrect update of current position in uncompressed buffer
- output_char was always writing spaces

Bam:
- length of certain NULL terminated sequences
- write of plain SAM header
- added more tests
bam_alt: now propose partial and complete parsing
moved check utility functions to internal_utils