parser.py: Writer class: write_record: samples order in template reader is checked and followed when outputting
model.py: Call class: aaf method: Always a value for each alternative allele is obtained
model.py: CallData: copy method created
model.py: Record class: merge method: problem solved in case of adaptation of alternative alleles
Improved samp filter performance, allow invert.
Args can be provided all at once or in sequence.

The latter style (filt3) allows semi-interactive at Python prompt.
rebase conflict
Actually write out sample-filtered file.
Switched Writer \r\n to os.linesep.
Fixed sample name list update/printing.
Moved all sample filtering to filter script.
Implemented argparse.
Tweak args, pep8, move empty outfile warning.
Fixed argparse arg names.
Changed default out to sys.stdout
rebase conflict
Added authorship statement.
Added sample filter to list of scripts in setup.
Moved sample filter object to src dir.
Using logging for easy quiet mode.
Unit test for sample filter module.
Docs/test for undo_monkey_patch