Utilize sequence multiplicities

[lczech]

Although non-standard, many sequence file preprocessing steps add meta-data to the sequence name. For example, in fasta, one often sees

>name_1234

or

>name;size=1234

in order to note the abundance of the sequence. Such formats are used e.g., by swarm and vsearch.

It would be helpful if epa-ng picks this information up and uses it as multiplicity in the result jplace file.