halStats command output should be consistently parsable

[diekhans]

Output in TSV format for halStats and other command as TSV would make it much easier to integrate into pipelines than the current ad-hoc formats.

[joelarmstrong]

This is already done in the progressiveCactus/hal master branches.

[joelarmstrong]

Oops, I misread. There are a few scripts that rely on halStats output being the way it is, but as long as we change those as well I don't really have objections to using TSV instead.

I did change it so that it is at least consistently CSV-ish (the coverage headers weren't really headers, and the number of fields in each line wasn't constant).