add lz4 code copyright/license in debian/copyright
add files
add function writing simple gzip header
add hwtreq field in BwtMergeTempFileNameSet class
add methods enumerateSymbolsInRangeSorted, enumerateSymbolsInRangeUnsorted and count in class ImpCompactHuffmanWaveletTree
add generic buffered gzip output classes and test
add CompactArrayWriter variant for files such that final size does not need to be known at construction time
add simple FM type index for DNA alphabets