Taxonomy: added functions to check if a taxonomy already exists in a

DMS, and added taxdump import from a compressed file

python/obitools3/apps/optiongroups/__init__.py

@@ -165,9 +165,9 @@ def __addTaxdumpInputOption(optionManager):
     group = optionManager.add_argument_group("Input format options for taxdump")
 
     group.add_argument('--taxdump',
-                     action="store", dest="obi:taxdump",
-                     default=None,
-                     help="Taxdump path")
+                     action="store_true", dest="obi:taxdump",
+                     default=False,
+                     help="Whether the input is a taxdump")
 
 def addMinimalInputOption(optionManager):
     __addInputOption(optionManager)