core/fasta.cpp: remove duplicate stdout message

Corrects bug introduced by 59a1bcf.
germlines.data: Dd2 and Dd3 rearrangements also include Vd-Dd3 and Dd2-Jd

Note that germlines.data is not used now. It will change soon.
split-from-imgt.py: display IMGT/GENE-DB license
split-form-imgt.py: factorize into 'verbose_open_w'
Tests: Test OnlineFasta
Tests: Add tests on Fasta
OnlineFasta: Useless copy constructor and operator= removed
Fasta: Remove unused 'out' constructor parameter
Tests: Tests fail when never executed
Tests: Fasta::add() wasn't actually tested.

Thanks to previous commit we can know catch those mistakes
Fasta: Throw rather than exit on error.

An exception can be caught while an exit can't. Thus we can test it.
Moreover some consistency is introduced: Fasta and OnlineFasta will
throw a invalid_argument in case of problem with the input file
(either in opening or parsing it).
Fasta: Test malformed FASTQ files
Tests: Test that nucleotides are uppercas-ed
Fasta: operator<< can now output FASTQ

When the Sequence contains quality information, it outputs a FASTQ rather than a FASTA.
This may be useful is one day we output FASTQ information (we never know, isn't it?)
Test: Test operator<< for Fasta and Sequence
Fasta: Remove additionnal line return

operator<< for Sequence already outputs one. No need to add another one
KMerAffect: Use AFFECT_UNKNOWN_SYMBOL and AFFECT_AMBIGUOUS_SYMBOL constants
Tests: test KmerAffect
Tests: Small test on IKmerStore
Fasta: Delete istream before throwing exception.

When exception is thrown from constructor, the destructor is not called