Change the syntax for the various priority options used by
merge-equivalent-sets. Instead of expecting a single string containing a
comma-separated list (e.g., `-s UBERON,CL,CARO`), the option should be
repeated for each prefix, in the desired order (e.g. `-s UBERON -s CL -s
CARO`).
To allow speciying priorities independently of the order of options on
the command line, we optionally allow specifying a score as follows: `-s
UBERON=10 -s CL=9`.
Damien Goutte-Gattat
1ace309064
