Update sallseqid attribute of BLAST tab results to create list

This field may contain multiple values, so a list is a more proper data
structure. The list is turned back into a string upon writing to a file.
Add parsing support for BLAST 2.2.28+ tab fields and its tests
Fix blast-tab bug where str(SeqRecord) instead of str(SeqRecord.seq) is written
Add new test for BLAST commented tab writing
Close handle in doctest
Simply doctests by using filenames for SeqIO
Simplify a doctest example using a filename with SeqIO
Fix use of deprecated assert_ method in RAXML test
Fix use of deprecated assert_ method in BGZF test
Close handles in test_geo.py
Close handles in test_Uniprot.py using context managers
Fix leaked handles in test_SeqUtils.py
Close handles in test_SubsMat.py using context managers
Fix handle leaks in test_TCoffee_tool.py by passing SeqIO filenames
Fix handle leaks in test_SeqIO_features.py
Replace deprecated assertEquals call with assertEqual
Fix another handle leak by using a context manager
Fix another handle leak by using a context manager
Ensure Astral FASTA handle is closed
Fix some more handle leaks