Improvements and bugfixes

Bugfix: BGCs from Others class would get added twice to that class. This
happened once when finding BGCs with mixed-type annotations, then again if
any of its sub-annotations was also from the Others class.
Improvement: Only read fasta and pfd files once when calling GCFs (instead of
doing it at each cutoff)
Improvement: Pass reduced distance matrix to clusterJsonBatch (so we can get
rid of it quickly)
Improvement: Pass already sorted list of BGCs to clusterJsonBatch
Improvement: improved human readability of .js file
Improvement: Cleaned and re-ordered arguments (a bit)
Other: Changed clan-calling parameter to '--clans'