[DOC] Gustaf: adapted README to new VCF output

git-svn-id: http://svn.seqan.de/seqan/trunk@14534 e6417c60-b987-48fd-844e-b20f0fcc1017
[FIX] Gustaf: windows compiler error wegen abs()

git-svn-id: http://svn.seqan.de/seqan/trunk@14535 e6417c60-b987-48fd-844e-b20f0fcc1017