Extend annot-tsv, adding several new options

[pd3]

-d, --delim
.. add support for other delimiters, not just tab

-h, --headers
.. allow header lines in different formats. This is motivated
by the common use of files with the first row containing
column names but without the leading # character.

-I, --no-header-idx
.. suppress column index numbers in the printed header. When
given twice, drops the entire header

--help
.. changed from -h, --help to just --help. Note this option
was not advertised in the man page nor the usage page,
therefore it should be okay to reuse it for -h, --headers.

[whitwham]

With a negative in the nth_row the first line of the actual data is missing in the output and memory is leaked from the strdup.

[whitwham]

Thanks for the memory leak change but the negative header values are still not working.

So (from the tests):
annot-tsv -s src.11.txt -t dst.11.txt -c chr1,beg1,end1:chr,beg,end -f smpl1:src_smpl -h 2:2 -II

gives:

1 10 20 A A
1 30 40 A B
1 50 60 A .

Which is correct, but using the same files:
annot-tsv -s src.11.txt -t dst.11.txt -c chr1,beg1,end1:chr,beg,end -f smpl1:src_smpl -h 2:-1 -II

gives:

1 30 40 A B
1 50 60 A .

So unless I'm using it wrong the first line is going missing.

[pd3]

Duh, it should work now, sorry