[Biopython] Removing deprecated BLAST HTML parser

[Peter]

Hi all,

The old HTML BLAST parser in Bio.Blast.NCBIWWW was deprecated
a year ago in Biopython 1.48, and in line with our deprecation policy I
would like to remove this for the next release.

Are there any objections?

The preferred BLAST output for parsing (as recommended by the NCBI
themselves) is XML. We also have a parser for the plain text output, but
this is not updated very frequently and the NCBI have a history of
making minor changes to the layout and breaking parsers.

Peter